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Biodiversity
Action Plan,
Gibraltar:
Planning
for Nature
Charles E. Perez
The Gibraltar Ornithological
and Natural History Society

Biodiversity Action Plan, Gibraltar: Planning for Nature
Copyright © 2006 The Gibraltar Ornithological & Natural History Society
Jews’ Gate, Upper Rock Nature Reserve, P.O.Box 843, Gibraltar.
Citation: Perez, C.E. (2006). Biodiversity Action Plan, Gibraltar: Planning for Nature.
The Gibraltar Ornithological & Natural History Society. Gibraltar.
Published by the Gibraltar Ornithological & Natural History Society.
Research and publication funded by the Overseas Territories Environment Programme (OTEP)
of the Foreign & Commonwealth Office of Her Majesty’s Government.
Printed and bound by Roca Graphics Ltd.
Tuckey’s Lane, Gibraltar. Tel. +(350) 59755 - From Spain: (9567) 59755

Contents
Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1) Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
What is Biodiversity. . . . . . . . . . . . . . . . . . . . . . . . . .9
The Biodiversity Convention . . . . . . . . . . . . . . . . .11
Gibraltar.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
The Significance of Biodiversity. . . . . . . . . . . . . . .13
Threats to Biodiversity . . . . . . . . . . . . . . . . . . . . . .14
The Gibraltar Action Plan . . . . . . . . . . . . . . . . . . . .16
2) The International Context. . . . . . . . . . . . . . . . . . . . .19
EU Birds Directive. . . . . . . . . . . . . . . . . . . . . . . . . .20
The Bonn Convention . . . . . . . . . . . . . . . . . . . . . .24
EUROBATS.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
ACCOBAMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Bern Convention . . . . . . . . . . . . . . . . . . . . . . . . . .28
CITES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
World Heritage Convention . . . . . . . . . . . . . . . . . .30
EC Habitats Directive . . . . . . . . . . . . . . . . . . . . . . .30
The Natura 2000 Network.. . . . . . . . . . . . . . . . . . .31
Convention on Biological Diversity . . . . . . . . . . . .32
Cartagena Protocol on Biosafety . . . . . . . . . . . . . .33
Alien Species. . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Biodiversity and Tourism . . . . . . . . . . . . . . . . . . . .34
Climate Change and Biodiversity . . . . . . . . . . . . . .34
Ecosystem Approach. . . . . . . . . . . . . . . . . . . . . . .34
Global Strategy for Plant Conservation.. . . . . . . . .35
Global Taxonomy Initiative.. . . . . . . . . . . . . . . . . . .35
Impact Assessment, Liability and Redress. . . . . . .35
Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Protected Areas . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Public Awareness and Education.. . . . . . . . . . . . .36
Sustainable use of Biodiversity . . . . . . . . . . . . . . .37
2010 Biodiversity Target . . . . . . . . . . . . . . . . . . . .37
3) Key Species & Habitats. . . . . . . . . . . . . . . . . . . . . . .41
4) Habitats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
Terrestrial Habitats . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
1 Upper Rock Nature Reserve.. . . . . . . . . . . . . . .52
2 Cliffs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
3 Lower Slopes and Buffer Zone.. . . . . . . . . . . . .59
4 Talus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
5 Great Sand Slopes. . . . . . . . . . . . . . . . . . . . . . .66
6 The Isthmus . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
7 South District . . . . . . . . . . . . . . . . . . . . . . . . . . .74
8 Urban Green Areas. . . . . . . . . . . . . . . . . . . . . . .81
9 Urban Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
10 Caves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89
Marine Habitats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93
11 Intertidal Zone . . . . . . . . . . . . . . . . . . . . . . . . .96
12 Artificial Reefs . . . . . . . . . . . . . . . . . . . . . . . . .99
13 Reefs & Inshore rocky outcrops . . . . . . . . . .101
13 Sand.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
14 Marl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
15 Rock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106
5) Species Action Plans . . . . . . . . . . . . . . . . . . . . . . ..109
Birds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110
Mediterranean Shag . . . . . . . . . . . . . . . . . . . . . . .110
Lesser Kestrel.. . . . . . . . . . . . . . . . . . . . . . . . . . .112
Peregrine Falcon. . . . . . . . . . . . . . . . . . . . . . . . . .113
Barbary Partridge . . . . . . . . . . . . . . . . . . . . . . . . .115
Eurasian Eagle Owl. . . . . . . . . . . . . . . . . . . . . . .116
Mammals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118
All Cetaceans.. . . . . . . . . . . . . . . . . . . . . . . . . . . .118
Barbary Macaque . . . . . . . . . . . . . . . . . . . . . . . . .120
Red Fox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122
European Rabbit. . . . . . . . . . . . . . . . . . . . . . . . . .123
Soprano Pipistrelle.. . . . . . . . . . . . . . . . . . . . . . . .124
Schreiber’s Bat . . . . . . . . . . . . . . . . . . . . . . . . . .125
Flowering Plants. . . . . . . . . . . . . . . . . . . . . . . . . .126
All Orchids.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126
Gibraltar Chickweed . . . . . . . . . . . . . . . . . . . . . . .128
Gibraltar Campion.. . . . . . . . . . . . . . . . . . . . . . . .129
Gibraltar Thyme . . . . . . . . . . . . . . . . . . . . . . . . . .130
Gibraltar Restharrow.. . . . . . . . . . . . . . . . . . . . . .131
Gibraltar Sea Lavender.. . . . . . . . . . . . . . . . . . . .132
Gibraltar Candytuft. . . . . . . . . . . . . . . . . . . . . . . .134
Gibraltar Saxifrage. . . . . . . . . . . . . . . . . . . . . . . .135
Sweet Bay or Laurel . . . . . . . . . . . . . . . . . . . . . .136
Narrow-leaved Ash . . . . . . . . . . . . . . . . . . . . . . . .137
Buprestis (Yamina) sanguinea ssp. calpetana . .138
Gibraltar Funnel-web Spider . . . . . . . . . . . . . . . .139
Acicula norrisi.. . . . . . . . . . . . . . . . . . . . . . . . . . . .140
Oestophora calpeana. . . . . . . . . . . . . . . . . . . . . .141
Mediterranean Ribbed Limpet . . . . . . . . . . . . . . .142
6) Alien, Invasive & Pest Species. . . . . . . . . . . . . . . .145
Alien Invasive Flora . . . . . . . . . . . . . . . . . . . . . . .148
Rooikrans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .149
Orange or Golden Wreath Wattle . . . . . . . . . . . .151
Pinwheel & Tree Houseleek . . . . . . . . . . . . . . . . .152
Century Plants. . . . . . . . . . . . . . . . . . . . . . . . . . .153
Tree of Heaven . . . . . . . . . . . . . . . . . . . . . . . . . .155
Tree Aloe & Soapy Aloe. . . . . . . . . . . . . . . . . . . .156
Hottentot Fig . . . . . . . . . . . . . . . . . . . . . . . . . . . .158
African Cornflag. . . . . . . . . . . . . . . . . . . . . . . . . .161
Purple Dewplant. . . . . . . . . . . . . . . . . . . . . . . . . .162
Bush Lantana or Shrub Verbena . . . . . . . . . . . . .163
Shrub Tobacco . . . . . . . . . . . . . . . . . . . . . . . . . . .164
Prickly Pear . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165
Bermuda Buttercup . . . . . . . . . . . . . . . . . . . . . . .168
Cape Wattle . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169
Kikuyu Grass. . . . . . . . . . . . . . . . . . . . . . . . . . . . .171
Cape Ivy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .172
Nasturtium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .174
Spineless Yucca . . . . . . . . . . . . . . . . . . . . . . . . . .175
Pest Species. . . . . . . . . . . . . . . . . . . . . . . . . . . . .176
Bear’s Breech . . . . . . . . . . . . . . . . . . . . . . . . . . .176
Black Rat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177
Feral Cat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179
Goat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .180
Feral Pigeon . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182
Yellow-legged Gull.. . . . . . . . . . . . . . . . . . . . . . . .184
7) References & Glossary
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .189
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .192
Contents
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Biodiversity Action Plan, Gibraltar: Planning for Nature
- 4 -
Foreword
The variety of plants and animals with which we share Gibraltar is truly remarkable. More and more
people are aware of this, but somehow I get the feeling that fewer and fewer get to experience it for themselves.
This is a problem. Lack of familiarity with the actual plants and animals that live around us means that
decision makers – from the developer and planner who formulates a project, or the politician who approves
it, to the builders who cut down the bush or disturb the nest – need to be constantly reminded of th consequence
of their actions, when really they should be so aware of these that their decisions will be strongly
influenced accordingly.
Having experts at hand is not good enough. They may forget to consult them, or decide, whether they
admit or not, to act regardless of advice. The only real way to ensure that the diversity of living things persists
and flourishes is for those on the front line to wish this to be so. And for that they need the knowledge.
Armed with that, it’s not so difficult. Often slight changes in plan will have the desired effect. At other
times ideas that seemed good may have to be significantly changed, or even abandoned.
The possible loss of biological diversity is one of the greatest environmental problems facing Gibraltar,
together, of course, with the problem of increasing demands on energy.
The Gibraltar Ornithological & Natural History Society (GONHS) has since its beginnings thirty years
ago, been at the helm of enjoying our biodiversity (well before we called it that) and protecting and enhancing
it.
It was therefore logical that now, at this point in Gibraltar’s journey through its history, it should synthesise
the wealth of knowledge it has accrued and provide a Plan that will serve to achieve these aims. We
produce this on the year of our 30 th Anniversary, in Gibraltar Biodiversity Year, a year too with other, political
landmarks. Political and constitutional progress, which is occurring in Gibraltar as I write, has to go
hand in hand with assuming responsibility for international obligations, with includes obligations to the environment
in general and biodiversity in particular.
Biodiversity Conservation is also increasingly a theme and an aim for organisations around the world,
not least the UK’s Overseas Territories and other small areas or regions.
Charlie Perez’s work sets out the basis for biodiversity conservation in Gibraltar, giving its background,
its international context, and then, while including a wealth of information, succinctly states what has to be
done.
While GONHS will continue to work to ensure that these principles find their way into action, much of
our collective work has been done. We present the Biodiversity Action Plan, providing the basis and throwing
down the challenge to those who now need to put it into effect.
John Cortes
General Secretary
The Gibraltar Ornithological & Natural History Society
2006

Acknowledgements
The author would like to thank the GONHS Biodiversity Team members Mr Leslie Linares, Mr Keith
Bensusan and Dr. John Cortes for their assistance in the many surveys of the different habitats that were
undertaken during the initial research period. To Dr Eric Shaw and Mr Steven Warr for their useful comments
on the Marine Habitats, to Mr Alex Menez for providing data and useful comments on the action
plans on the terrestrial molluscs, to Dr Darren Fa and Dr Terence Ocaña for providing data and useful comments
on the Mediterranean Ribbed Limpet.
The author is in debt to Mr Keith Bensusan for his invaluable contribution in the analysis of the status
of species in chapter 3 ‘Key Species and Habitats’ and to Mr Leslie Linares for his important contribution to
the knowledge of the flora of Gibraltar.
The author would also like to thank the Chief Fire Officer, Mr Louis Casciaro for providing information
on fire incidents, to the Committee of the Gibraltar Branch of the European Federation of Sea Anglers
(EFSA) for their useful comments on the marine environment and fish species, and to the photographers
Mr Leslie Linares, Mr Eric Shaw, Mrs Yvonne Benting, Dr John Cortes, Mr Albert Yome, Mr Julien Martinez,
Miss Torborg Berge, Mr Bob Wheeler and the Gibraltar Tourist Board for the use of their photographs and
to Miss Salli Menez for her fine drawings of the terrestrial molluscs. Distribution maps were produced using
DMAP for windows version 7.1f by Alan Morton.
Special thanks go to Wildlife (Gibraltar) for providing the office and equipment within the Gibraltar
Botanic Gardens at the Alameda to enable the production of the report.
The work involved in the production of this report was funded by the Overseas Territories Environment
Programme (OTEP) of the Foreign & Commonwealth Office. Thanks go to Denise Dudgeon and Rebecca
Claxton for their help and support in the administration of the Programme.
Thanks are also due to Dr Mike Pienkowski and to Frances Marks of the United Kingdom Overseas
Territories Conservation Forum for their encouragement and support.
Finally the author would like to express his gratitude to Mr Keith Bensusan, Dr. John Cortes, Dr. Ernest
Garcia and Mr Leslie Linares for their invaluable help in checking the manuscript.
Acknowledgements
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1. Introduction

Biodiversity Action Plan, Gibraltar: Planning for Nature
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1. Introduction
The ‘Convention on Biological Diversity’ was signed in 1993 and ratified by forty-three countries, including
the United Kingdom. Gibraltar, as part of this member state, was obliged to adopt this, but initially did
not take an active part in the implementation of the objectives of the Convention. In 2003, the Gibraltar
Ornithological & Natural History Society, realising the need to address some of these objectives, and with
an active base of naturalists and scientists and knowledge of the requirements, launched an initiative to catalogue
Gibraltar’s wildlife at a taxonomic level. The Gibraltar Biodiversity Project was launched by GONHS
on 28 th January 2004, and formed the initial step in bridging the gaps in our knowledge of the Biodiversity
of our territory. As part of this initiative, a proposal for funding was submitted to the UK Overseas Territories
Environment Programme of the Foreign and Commonwealth Office for the preparation of a Biodiversity
Action Plan for Gibraltar. This would encompass, not only the ongoing taxonomic assessments of the
Biodiversity of the territory, but also the need to identify areas at risk, encourage alternative sustainable use
and development, and more importantly create public awareness and participation, at all levels, on the significance
of Biodiversity as a strategic tool in the field of conservation. The bid was successful, and the
author of this report was engaged in August 2004 to prepare such a Plan.
This document is based on the UK’s Biodiversity Action Plan that was produced in 1995 under the headings
‘Biodiversity: The UK Steering Group Report. Volume I: Meeting the Rio Challenge’ and ‘Volume II:
Action Plans’ (HMSO 1995).
The Plan provides the background to the meaning and importance of Biodiversity at a global scale and,
using the UK Biodiversity Action Plan as a basis, translates this to the territory of Gibraltar and puts into
perspective the objectives and the requirements for making this Biodiversity Action Plan an operational success.
The report analyses historical accounts of Gibraltar’s environment and diversity of wildlife, and
describes the ‘progress’ and expansion of the human population and urbanisation through the centuries.
The ‘Habitats’ chapter covers our two main ecosystems - the terrestrial and the marine - both of which
are divided into distinct sites and habitat types, each with its unique species associations. Each has its own
action plan that describes the current status of the habitat and factors affecting its welfare, including existing
and potential threats, and the action required to remedy them. Another section stresses the need for
public awareness and involvement in Biodiversity Conservation at all levels, from an educational standpoint
to all other sectors of the community.
The ‘Gibraltar Biodiversity Project’ aims to catalogue as much of the flora and fauna of Gibraltar as possible,
in order to be able to assess the conservation requirements of species and habitats accurately. This
document emphasises the need for constant monitoring and research and invites public participation in the
‘Gibraltar Biodiversity Project’. It contains species lists for some of our flora and fauna and categorises
those species according to their conservation status and requirements. The document lists the serious
threats to our Biodiversity and addresses these in the Action Plan, where each particular problem is
addressed and remedial proposals, recommendations and targets are presented.
What is Biodiversity?
In the last quarter of the 20 th century, scientists were extremely worried at the rate of deforestation that was
taking place on a global scale, particularly in tropical regions. The tropical rainforests were known to hold the
highest number of species per unit area in the world but, with the continual loss of habitat, a great many were
being lost even before they could be described. There was a need to quantify the total number of species of
plants and animals in every region of the world, at local, regional and global levels. An assessment of Global
Biodiversity also had to take into account natural communities and habitats, since these are crucial to the
preservation of Biodiversity and serve as indicators of ecological change. The basic requirement to identify
and catalogue species within particular habitats and ecosystems, to assess species richness and diversity and
identify this diversity within natural communities, gave form to the term ‘Biological Diversity’, or as we now
know it ‘Biodiversity’.
The Oxford Dictionary of Ecology (Allaby, 1998) gives the meaning of Biodiversity as ‘A portmanteau
term, which gained popularity in the late 1980s, used to describe all aspects of biological diversity, especially
including species richness, ecosystem complexity, and genetic variation’. The meaning of
Biodiversity, given in A Dictionary of Entomology (2001) is ‘The condition of being different biologically‘. It
also quotes several definitions for this term from different scientists and organisations, which are repro-
Introduction
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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duced here to enable a clearer understanding of the term.
1. ‘…the variety of the world’s organisms, including their
genetic diversity and the assemblages they form. A blanket
term for the natural biological wealth that undergirds human life
and well-being. The breadth of the concept reflects the interrelatedness
of genes, species and ecosystems.’ (Reid & Miller
1989).
2. ‘The variety of living organisms considered at all levels,
from genetics through species, to higher taxonomic levels, and
including the variety of habitats and ecosystems’ (Meffe &
Carroll).
3. ‘…the variety and variability of living organisms and the
ecological complexes in which they occur.’ OTA.
Yet another definition that serves to clarify the complexities of biodiversity can be found in Reaka-Kudla
et al. (1997):
‘Biodiversity is defined as all heredity-based variation at all
levels of organisation, from the genes within a single population
or species, to the species composing all or part of a local community,
and finally to the communities themselves that compose
the living parts of the multifarious ecosystems of the world.’
We can see from the various meanings and interpretations that the key elements of Biodiversity are
species richness, ecosystems and genetic variability. These three elements are therefore the basis for
much of the coordinated work of scientists around the world to establish the biological wealth within ecosystems
and thereby consolidate conservation efforts aimed, not only at protecting the natural environment but
also at making its sustainable use possible. Our long-term survival depends on it.
Nevertheless the number of species that exists globally is unknown. Some estimate the total number
of species at between 5 and 30 million (HMSO 1995), while others believe it to be between 10 and100 million
(Reaka-Kudla et al. 1997). We can see from these figures a remarkable disparity, which emphasises
the level of our current knowledge.
1,6%
2,4%
1,6%
0,4%
6,7%
7,7%
3,2%
4,0%
64,4%
Bacteria
Virsus
Insects
Protozoa
Algae
Plants
Vertebrates
Other invertebrates
Other arthropods
Figure 1. Estimated percentage of species from different groups of organisms thought to exist, as
a proportion of the global total. (Source: ‘Biodiversity: The UK Steering Group Report’. (1995)).

Notwithstanding this, some countries have achieved substantial progress in cataloguing their
Biodiversity. This is particularly useful when applying these same findings towards Biodiversity action
plans. In the United Kingdom, as elsewhere, microbial organisms such as bacteria and protozoa are less
well known than invertebrates. However, the larger, more visible and attractive taxonomic groups, such as
flowering plants and vertebrates have been intensively studied and have received more attention. Many
British invertebrate groupings have also been studied intensively but every taxonomic group deserves
equal attention.
A sound knowledge of local faunas is essential for conserving native species. Some require monitoring
to assess their specific requirements, establish their populations and determine their status at local and
national levels. This can only be done by identifying which habitats they occupy and the threats that these
are subject to, which can then be addressed.
Table 1: Numbers of terrestrial and freshwater species in the UK compared
with recent global estimates of described species in major groups.
Group British species World species
Bacteria Unknown >4,000
Viruses Unknown >5,000
Protozoa >20,000 >40,000
Algae >20,000 >40,000
Fungi >15,000 >70,000
Ferns 80 >12,000
Bryophytes 1,000 >14,000
Lichens 1,500 >17,000
Flowering Plants 1,500 >250,000
Non-arthropod invertebrates >4,000 >90,000
Insects 22,500 >1,000,000
Arthropods other than insects >3,500 >190,000
Freshwater fish 38 >8,500
Amphibians 6 >4,000
Reptiles 6 >6,500
Breeding birds 210 9,881
Wintering birds 180 n/a
Mammals 48 4,327
Total c.88,000 c.1,770,000
Source: - ‘Biodiversity: The UK Steering Group Report’. (1995).
It is necessary to realise that Biodiversity, although associated with species diversity to a great degree,
also encompasses the interrelationship between species and their habitat. This link is of vital importance
since it is what has promoted the gradual evolution through time of new varieties and species. So far, this
natural process has only been disrupted occasionally through abrupt but natural climatic changes, some of
them resulting from catastrophic events such as asteroid impacts. However, we are now aware that today,
global Biodiversity is gravely threatened by human activity.
The realisation that biodiversity is declining, noted by scientists all around the world, prompted many
countries to take action. This led to the Earth Summit in Rio de Janeiro in June 1992, where the Convention
on Biodiversity was established.
The Biodiversity Convention.
The term ‘BioDiversity’, as it was initially written, was first used during the ‘National Forum on
BioDiversity’, held in Washington during September 1986, under the auspices of the National Academy of
Sciences and the Smithsonian Institution (Reaka-Kudla et al. 1997). In 1992, at the Earth Summit in Rio
de Janeiro, 167 countries became signatories to the Convention on Biological Diversity, and by 1993, 41
countries had ratified it. This was the first time that a large majority of the world’s states had come togeth-
Introduction
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Biodiversity Action Plan, Gibraltar: Planning for Nature
- 12 -
er and agreed on a legal instrument that would commit them to using biological resources sustainably and
conserving biodiversity. This Convention had global perspectives. All the states realised that the problems
that affect the global environment have to be addressed by all countries of the world for the benefit, and
indeed survival, of mankind.
The three main objectives of the Convention are in Article 1:
• the conservation of biodiversity at the genetic, species and ecosystem levels.
• the sustainable use of its components; and
• the fair and equitable sharing of benefits derived from the use of genetic
resources.
The United Kingdom was a signatory of the Convention on Biological Diversity and Gibraltar, as a territory
of the UK, is obliged to adopt the Convention and comply with and enforce its goals and objectives.
The United Kingdom launched ‘Biodiversity: The UK Action Plan’ in January 1994, and established representatives
for a Biodiversity Steering Group from key sectors chaired by the Department of the Environment
who would oversee the following tasks: -
• Developing costed targets for key species and habitats.
• Suggesting ways of improving the accessibility and coordination of information on
Biodiversity.
• Recommending ways of increasing public awareness and involvement in conserving
Biodiversity.
• Recommending ways of ensuring that commitments in the plan were properly
monitored and carried out; and
• Publishing findings before the end of 1995.
The Group was selected to represent regional and local Government from private and public sectors,
academic bodies, collections, business, agriculture, landowners, and conservation NGOs. Primarily in an
advisory capacity, the proposals contained within the report were then submitted to Government for action
(HMSO 1995).
Gibraltar.
The United Kingdom, with responsibility for Gibraltar, published these findings in their ‘Biodiversity: The
UK Steering Group Report’ Volumes I and II (HMSO 1995), where they refer to Gibraltar in ‘Annex B’ under
the ‘Dependent Territories Progress Report’.
Figure 2: Gibraltar viewed from the south. Courtesy Gibraltar Tourist Board.

Gibraltar figures in the UK Steering Group Report as ecologically significant and sensitive, stemming
from its location on a major migration route, with very substantial flora for its area and important marine biological
assets, but vulnerable because of its small area with a high population. The Steering Group recognised
the sound, scientifically based work that has been carried out in Gibraltar over a number of years and
they welcome the implementation of the ‘Nature Protection Ordinance, 1991’ and the creation of the Upper
Rock Nature Reserve, together with transposition of EU directives. They also state that Gibraltar has implemented
the Habitats Directive (the Directive has been transposed into the laws of Gibraltar (Part II A, LN
118 of 1995), but the designation of Natura 2000 sites is pending).
The report recognises the excellent human resources backing the conservation efforts in the form of the
Gibraltar Ornithological & Natural History Society and the partnership that exists between this organisation
and the Gibraltar Government, providing expert advice and preparing reports. It also mentions that
Gibraltar was being considered as a location for one of the global Geographical Observatories under a programme
initiated by the Royal Geographical Society, and refers to lack of funding for biodiversity conservation
as the main problem facing Gibraltar in this context.
The Significance of Biodiversity.
We have discussed the meaning of Biodiversity and how numerous countries worldwide are now committed
to improving the quality and quantity of their fauna and flora, in order to ensure that future generations
will be able to inherit a healthy environment. However, during the recent history of mankind the uncontrolled
use, and in many cases the abuse of the Earth’s ecosystems, have led to a degradation of the land,
the seas and the air. Species-loss has been severe and irreversible in every part of the globe, and mankind
has largely ignored the interdependency of living organisms, leading to a collapse in the balance of nature
and an impoverishment of biological resources for the future.
The use and abuse of unsustainable resources has resulted in many natural catastrophes around the
world including increased desertification in many areas and the depletion of the ozone layer over both
poles. It has also led to the realisation that mankind is affecting the weather systems through climatic
change, including global warming, leading to sudden short term alterations in ecosystems that are too rapid
for evolutionary adjustments to keep up. If such climate change is allowed to continue, this will eventually
result in dramatic loss of biodiversity.
Humans are dependent on the terrestrial and marine environments for all our requirements. However,
the increasing demands placed on these ecosystems and the continued growth of the human population
has placed increased pressures to augment the rate of production of commodities. This has resulted in the
loss of much of our natural environment, and has brought about the realisation by many that if we do not
conserve our Biodiversity, the long-term future of the human species will be in doubt.
So why conserve Biodiversity?
1) Primarily we have an obligation to future generations. We have created most of the recent
dramatic changes in our ecosystems and, as custodians, are responsible for ensuring that
these same ecosystems do not suffer continual degradation and that the biodiversity of these
systems is conserved.
2) There are also ethical and aesthetic implications. The environment, together with its habitats
and species living within the same, enriches our lives in a variety of ways. We have all
heard our older relatives say at one time or another, “I remember how beautiful this place
used to look like, before it …”
3) Each species has a particular value and plays a particular role in nature. Many animals and
plants are directly useful to us and ever more beneficial species are steadily being discovered.
Crop plants and domestic animals are the most obvious examples. In addition, there
are those which rid us of pests that would otherwise eat our crops or spread disease. Others
provide us with medicinal remedies for a multitude of ailments. Still more provide building
material, act as water filters or prevent erosion. A whole range of bacteria and plant species
are vital to the nutrient cycles, such as the circulation of nitrogen, which make any life on
earth possible. Green plants provide us with the very oxygen we breathe.
Introduction
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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4) Biodiversity has direct economic value. The development of national Parks and nature
reserves around the world and increasing interest in the wildlife has generated the industry
of Ecotourism, which is bringing great economic benefits to many countries.
Threats to Biodiversity
Many major threats worldwide affect Biodiversity. The most important ones include:
• Overpopulation: leading to ever-increasing demands for food, water and living space, and
increased pollution, all at the expense of natural environments.
• Habitat destruction, especially deforestation
• Greenhouse gas emission: of carbon dioxide and methane, potentially contributing to global
warming including climate change.
• Over-harvesting of potentially sustainable resources: over-fishing especially.
• Urbanisation of natural habitats
• Non-sustainable use of water.
• Loss of genetic diversity among crop plants and animals.
• Impacts of alien species on indigenous communities: the extinction of island bird communities
by introduced rats and snakes is a prime example.
• Trade in endangered species: such as tigers and rhinoceroses, and in their products: such
as ivory and whale-meat.
The two most notable are habitat loss and pollution. These issues are most frequently associated with
the felling and burning of tropical forests and the emission of greenhouse gases into the atmosphere.
These two account for the most significant changes that have occurred recently. The results of the
gases and the depletion of the large masses of oxygen-producing forests have resulted in a slight but significant
increase in the temperature of the planet. This has led to substantial changes in some ecosystems.
Glaciers have retreated and in some places disappeared altogether. The ice-sheets around the poles have
been gradually thinning and shrinking. Temperatures in the waters of the east Pacific show an increase
that affects the fluctuations that give rise to the phenomena called ‘El Niño’ and ‘La Niña’. Their power
appears to have intensified as a result of this increase, and this has been the cause of torrential rains in
coastal South America, while at the same time causing the failure of the monsoon rains in the Indian subcontinent,
and extensive droughts in eastern Australia triggering immense forest fires. Temperature
increases in the mid Atlantic have spawned larger, more frequent and more ferocious hurricanes affecting
the Caribbean, the Gulf of Mexico and the southern states of the United States. Likewise there has been
an increase in the quantity and ferocity of typhoons affecting the eastern seaboard of Asia (IPCC 2001).
These are some of the major ‘natural catastrophes’ that make the headlines. Each causes human
tragedies, destruction, homelessness, strife, starvation, diseases and general despair. It is usually measured
in countless millions of dollars, but that only quantifies the human losses. What about the irreparable
losses to habitats and the deaths of whole communities of plants and animals? These never make the
headlines, but the tragedy is just as serious and in many cases worse. Agricultural and farming practices
rely on ecological conditions, and these may be affected by a loss of habitats and biodiversity.
This is the time for mankind to wake up and realise that we are not alone on this planet. That the planet
is not endowed with an infinite supply of raw materials and that our actions have far more long-term
effects than we ever realised.
It is only in the last 30 years that we have begun to realise that the continual harvesting of certain commodities
has exceeded the natural regeneration rate. This has resulted in the depletion of certain species,
one of which led to the infamous ‘Cod Crisis’ in North Atlantic waters in the 1970’s and the establishment
of a quota system, which has nevertheless been unsuccessful, due to unscrupulous fishing practices and
quota bypassing elements (Nielsen & Mathiesen 2003). Another example is the uncontrolled felling of hardwood
timber and the establishment of import bans which many countries do not apply or enforce, while others
turn a blind eye, and encourage the countries of origin to part with their rich tropical forests. These are
just some examples that have driven major countries to adopt a policy of sustainability, in which stocks of
certain commodities will only be harvested on the basis that there will always be sufficient left to ensure that
future stocks are assured.
There are also the threats to habitats, where building pressures for development and the expansion of

major towns and cities have sown the destruction of many of our green areas and wetland habitats. If we
take into account that during the early part of the last millennium most of the transport system consisted of
either horse-drawn carriage or waterborne vessels, and this last method was the most efficient, it is then
not surprising that most towns and cities were located on major waterways and coastal locations. The
rivers acted not only as navigational routes but also for the provision of water and the disposal of effluent.
Over the centuries these cities have grown, taking in the flat terrain of the riversides and floodplains to
expand. Cities like London have taken up an enormous area of the Thames valley and with it industrial
sites have benefited from the proximity to rivers, initially to run machinery and dump waste but mainly as a
transport waterway. These rivers have been polluted to a great extent, diminishing the wildlife of these wetland
ecosystems. Marshes have been drained, peat bogs have been cleared and estuaries have been
reclaimed and their rivers channelled. There has been a drastic reduction of wetlands in the northern hemisphere
in the last 200 years, with a large percentage of these extremely diverse habitats disappearing in
recent times, to be turned over to agriculture.
Unsound agricultural practices, with mounting pressures to increase demand for an expanding population
have resulted in rampant deforestation and destruction of natural habitats. In many areas, only small
pockets of isolated natural areas that are unsuitable for farming remain. These are insufficient to contain a
viable thriving community of plants and animals, and studies have shown that small, isolated populations
do not survive for very long. Monoculture techniques over large areas have also limited the variability of
species and have opened up a niche for pest species to target. Ironically, this has led to unnatural control
with pesticides and herbicides that have wiped out not only the pest species, but other beneficial species
that could have been used as a natural control. Here again we see the destruction of Biodiversity at the
level of habitats and species without consideration for the future exploitation of these resources, and carried
out in a totally unsustainable manner.
There is also the use of unsustainable energy sources in the form of fossil fuels, which are extracted
from the mantle of the planet, leaving behind profound scars in the landscape and contaminating everything
it comes into contact with. The extraction of coal in the early 20 th century gave way to oil when it
became apparent that resources of the latter were uneconomical to extract and running low. The industrial
revolution in the 1800’s spurred the need for unlimited supplies of fuel, which in turn produced the smogladen
air of that time and initiated the contamination of the earth’s atmosphere. When oil replaced coal,
industry had already evolved at a relentless pace, and with the invention of the combustion engine, oil and
its derivatives became the answer to the world’s energy problems.
Although essential at the time for the modernisation of society, the unrelenting use of unsustainable
energy resources has invariably affected Biodiversity through contamination and pollution of many natural
ecosystems. It is time for mankind to seek more environmentally stable and sustainable renewable forms
of energy to redress this loss.
Figure 3: Atmospheric pollution from the Spanish Refinery to the north of Gibraltar.
Introduction
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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The introduction of alien and/or invasive species is another aspect that has seriously affected the
Biodiversity of our planet. In the age of discovery, when adventurers set sail to discover new lands, they
took with them cats to control vermin, namely the black rat, Rattus rattus, that regularly travelled on these
ships. Both these species were to find their way onto dry land, in areas of the world that were basically virgin
territory to these two species. Here, without any natural controlling factors, the two proliferated and
preyed on or excluded the native species. In many parts of the world these two species have exterminated
and caused the extinction of the most number of species, other than man. In New Zealand, where there
was a rich native population of flightless birds, cats and rats took an immense toll on the avifauna, completely
exterminating many species. Even today there are certain islands in the Pacific Ocean where there
is a current extermination programme of cats and rats, in order to save the native population of seabirds.
There are many other similar examples.
We can see the damage done to ecosystems when there are no natural predators to control animals,
but what can one do when the alien species is not an animal but a plant? Few people realise the problems
that an invasive plant can cause, yet the introduction of plant species in an area where there again is no
natural controlling factor, is a recipe for disaster. It was common practise for the sailors returning from exotic
locations to bring back colourful and exotic plants and flowers. Many did not survive the harsh northern
European climate except in greenhouses, under artificial conditions. Yet some fared better and proliferated
escaping through wind blown seed and other means into the wild, where they established successful
colonies and pushed out native species. An example can be found in the UK where the Rhododendron,
Rhododendron ponticum has invaded and become a pest species.
These are some of the major threats that affect our Biodiversity. Some are spurred on by necessity, for
want of a mouthful today, others through greed. Nevertheless many threats occur through ignorance: ignorance
of the fact that what we do as an individual will not affect all of us on this planet. Yet we are all linked
together in one way or another, from the smallest virus and bacterium to the largest animals. We humans
often believe that we are leaders in the evolutionary ladder. But a leader has responsibilities, and since we
have created most of the dramatic changes that have taken place on our planet we have a moral obligation
to put this right.
The Gibraltar Action Plan
This Plan highlights the importance of biodiversity in Gibraltar and aims to provide specific habitat and
species action plans that will address the overall goal for Gibraltar’s Biodiversity requirements. This is:
“To conserve and enhance biological diversity within
Gibraltar and to contribute to the conservation of global
biodiversity through all appropriate mechanisms.”
The objectives of the Biodiversity Action Plan, within both our terrestrial and marine ecosystems, are
therefore:
• To sustain the existing biodiversity of natural and semi-natural habitats where
this has been declining.
• To conserve internationally important, threatened and vulnerable species and habitats.
• To sustain the populations and distribution of native species.
• To conserve and improve the quality of natural habitats.
• To increase total biodiversity, by reintroducing locally extinct species.
• To restore natural habitats by controlling and eradicating alien species.
The Gibraltar Biodiversity Project will establish and identify key species and habitats and will
provide the bases for the necessary nature conservation programmes and tasks. These will
need to be tackled by the Gibraltar Government and their agencies, in consultation and in partnership
with existing environmental NGO’s and will require the collaboration of developers and
other stakeholders.
The programmes will require costed targets for threatened species and habitats that will include research
and monitoring, increasing public awareness and involving other key sectors.
Such programmes will address the requirements for conserving the biodiversity of Gibraltar and will
reveal what is required to tackle other important environmental issues.

2. The International Context

Biodiversity Action Plan, Gibraltar: Planning for Nature
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2. The International Context
The survival of much of Europe’s natural environment, its fauna, flora and habitats were under unremitting
and increasing threats and all had deteriorated substantially by the mid to late 1900’s. One of the
European Union’s primary tasks was to halt the increasing threats to habitats, prevent species loss, and
protect and conserve Europe’s biodiversity. Through a continuous process of developing environmental legislation,
with the application of European Directives addressing threatened species and habitats, and the
establishment of networks of protected areas, the European Union and its Member States have come a
long way in the process of achieving these objectives. Nevertheless this is an ongoing process that
requires continual monitoring, evaluation and reporting, and one that benefits from public participation.
Organisations such as the World Conservation Union (IUCN) are continually monitoring wildlife and have
also assessed the need to protect species at a global level and published the IUCN Red List Criteria. They
have also made recommendations that have led to international agreements such as CITES (the
Convention on the International Trade in Endangered Species) that have been ratified by the United
Kingdom and apply to Gibraltar. Birdlife International is another organisation that has also assessed the status
of Europe’s avifauna in their publications Birds in Europe I (Tucker & Heath 1994) and Birds in Europe II
and established two Important Bird Areas (IBAs) for Gibraltar (Birdlife International 2004). Their assessment,
and those of IUCN and other organisations dealing with the protection of wildlife on a global scale,
complements EU Regulations and Directives by providing the mechanisms for the establishment of protected
areas and the conservation of the habitats of endangered species.
Gibraltar, as a European Territory of the Member State (the United Kingdom) which has ratified these
Conventions, Directives and Agreements, is obliged to conserve and protect its unique wildlife and habitats,
and to implement the above measures.
Several international instruments apply in part or in full to the Territory of Gibraltar. Some deal specifically
with certain groups of animals: for example, the EU Wild Birds Directive, the Convention on Migratory
Species (CMS) and EUROBAT that aims to protect all European bat species. Others incorporate the protection
of habitats as well as defining priority species in need of conservation, and have given rise to a
series of environmentally important areas within Member States that form or will form networks of protected
areas under the name of ‘Natura 2000 Network’ or ‘The Emerald Network’. One particular agreement:
‘ACCOBAMS’, which deals only with the conservation of cetaceans within the Black and Mediterranean
seas and the adjacent part of the Atlantic Ocean, was ratified by the United Kingdom in view of Gibraltar’s
location and has no direct relevance to the British Isles.
This chapter explains the main provisions and objectives that deal with species and their habitat requirements
within these Conventions and Directives and sets out how the relevant measures apply to Gibraltar.
Table 1 lists the Conventions and agreements that have been ratified by the United Kingdom and that
apply to Gibraltar.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Table 1: Main Environmental Conventions, Directives and Agreements
dealing with wildlife that apply or have been transposed in Gibraltar.
EU Birds Directive The Directive on the Conservation of Wild Birds 79/409/EEC
Bonn Convention Convention on the Conservation of Migratory Species of
Wild Animals 82/461/EEC
Bonn Convention Agreement on the Conservation of Populations of European Bats
- EUROBATS
ACCOBAMS Agreement on the Conservation of Cetaceans of the Black
Sea, Mediterranean Sea and contiguous Atlantic area
CITES The Convention on the Trade in Endangered Species of
Wild Flora and Fauna
World Heritage The Convention concerning the Protection of the
Convention World Cultural and Natural Heritage
EC Habitats Directive The Conservation of Natural Habitats and Wild Fauna
and Flora 92/43/EEC
Natura 2000 Network A network of protected areas set up under the Birds and
Habitats Directives
Biodiversity Convention The Rio de Janeiro Convention on Biological Diversity
93/626/EEC
EU Birds Directive
The European Unions’ Birds Directive came into force on 2 April 1979. It was incorporated into the
United Kingdoms Wildlife and Countryside Act 1981 as the principle vehicle in implementing this Directive.
The Directive is divided into two main parts: habitat conservation and species protection. For rare and
endangered species the Directive recommends the creation of protected areas by the implementation of
Special Areas of Protection (SPAs), with the appropriate management and the creation of new habitats and
restoration of existing habitats.
It also requests Member States to prohibit the deliberate killing of wild birds, damage to their nests or
eggs, the taking or keeping of eggs of wild birds, and the keeping of wild birds and deliberate disturbance
in their habitats especially during the breeding season.
Box 1 lists the main provisions that deal specifically with the protection of birds and their habitats.
1. Strictly for European wild birds and their habitats. Adapted from Birds in Europe (2004).
EU Wild Birds Directive (79/409/EEC)
• Article 1……. reports on the conservation of wild species of birds found naturally in the
European territory of the Member States, and this applies to birds and includes their eggs, nests
and their habitats.
• Article 2……... calls for the Member State take adequate measures to maintain the stable population
of the species referred to in Article 1 to a degree that incorporates the scientific, cultural
and ecological requirements whilst taking into account economic and recreational requirements,
or adapt the population of these species to that level.

• Article 4.1…… calls for the Member State to take special measures in habitat conservation to
ensure the survival and reproduction of species listed in Annex I that are (a) in danger of extinction;
(b) vulnerable to specific changes in their habitat; (c) considered rare, because of small
populations or restricted local range; or (d) in need of particular attention, due to their specific
requirement and nature of their habitat.
• Member States are required to classify suitable areas in number and size as ‘Special Protection
Areas’ or SPAs, for the conservation of these species as well as regularly occurring migratory
species, (covered in Article 4.2), taking into account their protection requirements in the terrestrial
and marine areas where the Directive applies.
• Monitoring the changes in trends and population levels are also required by the Directive for the
purpose of evaluating the conservation of species within the Member States
The Directive lists the 181 wild bird species that are classified as in need of protection under Annex I.
Annex I species of the Directive are the subject of special conservation measures to ensure their survival
and reproduction in their areas of distribution. Member States also require to consider similar measures
for regularly occurring migratory species not listed in Annex I, bearing in mind their need for protection in
the geographical sea and land area where this Directive applies, as regards their breeding, moulting and
wintering areas and staging posts along their migration routes.
In Gibraltar, the Birds Directive was incorporated under the Nature Protection Ordinance1991 (LN 11 of
1991), which affords protection to all species of wild birds. Some of the wild birds that have been recorded
in Gibraltar, as resident, summer or winter visitors, or on migration, include 88 species that are included in
the Birds Directive under Annex I and these are the subject of European special conservation measures.
They represent 48.6% of the bird species in Annex I. Gibraltar bird species that figure in Annex 1 are listed
in Table 2.
Table 2: Local status of bird species listed in Annex I of
Council Directive 79/409/EEC that have been recorded in Gibraltar.
Population
Migratory
Name Resident Breed Winter Stage
Aegypius monachus 1-5i
Alcedo atthis 1-5i 1-5i
Alectoris barbara 50p
Anthus campestris 11-50i
Bubo bubo 1p
Calandrella brachydactyla 1-5i
Calonectris diomedea >10000i
Caprimulgus europaeus 6-10i
Chlidonias niger 101-250i
Ciconia ciconia 251-500i
Ciconia nigra 11-50i
Circaetus gallicus 251-500i
Circus aeruginosus 101-250i
Circus cyaneus 1-5i
Circus pygargus 101-250i
Emberiza hortulana 11-50i
Falco columbarius 1-5i
Falco eleonorae 6-10i
Falco naumanni 11-15p 11-50i
Falco peregrinus 6-10p
Falco tinnunculus 5p 51-100i
Gelochelidon nilotica 1-5i
Gyps fulvus 51-100i
Hieraaetus fasciatus 1-5i
Hieraaetus pennatus 1-5i 251-500i
Larus audounii 51-100i 1001-10000i
Larus melanocephala 11-50i 501-1000i
Lullula arborea 1-5i
Luscinia svecica 1-5i
Melanitta nigra 11-50i
Milvus migrans >10000i
Neophron percnopterus 51-100i
Oceanodroma leucorhoa 11-50i 51-100i
Pandion haliaetus 11-50i
i = individuals; p = pairs.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Population
Migratory
Name Resident Breed Winter Stage
Pernis apivorus >10000i
Ph. aristotelis desmaresti 5p
Ph. carbo sinensis 1-5i
Puffinus mauretanicus 11-50i 1001-10000i
Sterna albifrons 6-10i
Sterna caspia 1-5i
Sterna hirundo 11-50i
Sterna sandvicensis 11-50i 251-500i
Sylvia undata 11-50i 11-501
i = individuals; p = pairs.
Table 3: Bird Species listed in Annex I of the Birds Directive 79/409/EEC
that have been recorded in Gibraltar.
Latin name Species
Gavia stellata Red-throated Diver
Gavia immer Great Northern Diver
Calonectris diomedea Cory's Shearwater
Puffinus mauretanicus Balearic Shearwater
Puffinus assimilis Little Shearwater
Hydrobates pelagicus Storm Petrel
Oceanodroma leucorhoa Leach's Storm-petrel
Phalacrocorax aristotelis desmarestii Shag (Mediterranean sub-species)
Ixobrychus minutus Little Bittern
Nycticorax nycticorax Night Heron
Ardeola ralloides Squacco Heron
Egretta garzetta Little Egret
Ardea purpurea Purple Heron
Ciconia nigra Black Stork
Ciconia ciconia White Stork
Plegadis falcinellus Glossy Ibis
Platalea leucorodia Spoonbill
Phoenicopterus roseus Greater Flamingo
Pernis apivorus Honey Buzzard
Elanus caeruleus Black-shouldered Kite
Milvus migrans Black Kite
Milvus milvus Red Kite
Gypaetus barbatus Bearded Vulture
Neophron percnopterus Egyptian Vulture
Gyps fulvus Griffon Vulture
Aegypius monachus Black Vulture
Circaetus gallicus Short-toed Eagle
Circus aeruginosus Marsh Harrier
Circus cyaneus Hen Harrier
Circus macrourus Pallid Harrier
Circus pygargus Montagu's Harrier
Buteo rufinus Long-legged Buzzard
Aquila pomarina Lesser Spotted Eagle
Aquila clanga Greater Spotted Eagle
Aquila adalberti Spanish Imperial Eagle
Aquila chrysaetos Golden Eagle
Hieraaetus pennatus Booted Eagle
Hieraaetus fasciatus Bonelli's Eagle
Pandion haliaetus Osprey
Falco naumanni Lesser Kestrel
Falco columbarius Merlin
Falco eleonorae Eleonora's Falcon
Falco biarmicus Lanner Falcon
Falco peregrinus Peregrine
Latin name Species
Alectoris barbara Barbary Partridge
Porphyrio porphyrio Purple Gallinule
Grus grus Crane
Otis tarda Great Bustard
Himantopus himantopus Black-winged Stilt
Recurvirostra avosetta Avocet
Burhinus oedicnemus Stone Curlew
Glareola pratincola Collared Pratincole
Pluvialis apricaria Golden Plover
Limosa lapponica Bar-tailed Godwit
Larus melanocephalus Mediterranean Gull
Larus genei Slender-billed Gull
Larus audouinii Audouin's Gull
Gelochelidon nilotica Gull-billed Tern
Sterna caspia Caspian Tern
Sterna sandvicensis Sandwich Tern
Sterna dougallii Roseate Tern
Sterna hirundo Common Tern
Sterna paradisaea Arctic Tern
Sterna albifrons Little Tern
Chlidonias hybridus Whiskered Tern
Chlidonias niger Black Tern
Pterocles alchata Pin-tailed Sandgrouse
Bubo bubo Eagle Owl
Asio flammeus Short-eared Owl
Caprimulgus europaeus Nightjar
Apus caffer White-rumped Swift
Alcedo atthis Kingfisher
Coracias garrulus Roller
Melanocorypha calandra Calandra Lark
Calandrella brachydactyla Short-toed Lark
Galerida theklae Thekla Lark
Lullula arborea Woodlark
Anthus campestris Tawny Pipit
Luscinia svecica Bluethroat
Oenanthe leucura Black Wheatear
Sylvia sarda Marmora's Warbler
Sylvia undata Dartford Warbler
Ficedula parva Red-breasted Flycatcher
Lanius collurio Red-backed Shrike
Pyrrhocorax pyrrhocorax Chough
Bucanetes githagineus Trumpeter Finch
Emberiza hortulana Ortolan Bunting

Table 4: Local status of regularly occurring migratory
birds not listed in Annex I of the Birds Directive.
Population
Migratory
Name Resident Breed Winter Stage
Accipiter nisus 101-250i
Anthus pratensis 51-100i 501-1000i
Anthus trivialis 50-100i
Alca torda 11-50i 1001-10000i
Apus apus 2000p >10000i
Apus melba 25p 251-500i
Apus pallidus 2000p 1001-10000i
Buteo buteo 1-5i 251-500i
Calandrella rufescens 11-50i
Caprimulgus ruficollis 6-10i
Carduelis cannabina 11-50i 1001-10000i
Carduelis carduelis 51-100i 1001-10000i
Carduelis chloris 15p 51-100i 1001-10000i
Carduelis spinus 11-50i 251-500i
Catharacta skua 6-10i 101-250i
Cercotrichias galactotes 1-5i
Certhia brachydactyla 6-10i
Cisticola juncidis 1-5p 11-50i 101-50i
Coturnix coturnix 11-50i
Cuculus canorus 6-10i
Delichon urbica 6-10p 1001-10000i
Erithracus rubercula 1-5p 251-500i 1001-10000i
Falco subbuteo 11-50i
Ficedula hypoleuca 251-500i
Fratercula arctica 1001-10000i
Fringilla coelebs 1-5p 101-250i 1001-10000i
Galerida cristata 1-5i 11-50i
Hippolais pallida 1-5i
Hippolais polyglotta 1001-10000i
Hirundo daurica 51-100i
Hirundo rustica 1001-10000i
Jynx torquilla 1-5i 51-100i
Lanius excubitor 1-5i
Lanius senator 101-250i
Larus fuscus 51-100i 1001-10000i
Larus ridibundus 251-500i 1001-10000i
Locustella naevia 11-50i
Luscinia megarhynchos 1001-10000i
Merops apiaster 1001-10000i
Miliaria calandra 1-5i 51-100i
Motacilla alba 101-250i 501-1000i
Motacilla cinerea 11-50i 501-1000i
Motacilla flava 501-1000i
Muscicapa striata 501-1000i
Oenanthe hispanica 251-1000i
Oenanthe oenanthe 251-1000i
Oriolus oriolus 11-50i
Otus scops 6-10i
Phoenicurus ochrurus 501-1000i 1001-10000i
Phoenicurus phoenicurus 1001-10000i
Phylloscopus bonelli 1001-10000i
Phylloscopus collybita 501-1000i 1001-10000i
Phylloscopus trochilus 1001-10000i
Prunella collaris 11-50i
Prunella modularis 11-50i
Ptyonoprogne ruprestis 251-500i 1001-10000i
Puffinus gravis 1-5p
Puffinus griseus 6-10i
Regulus ignicapillus 11-50i
Riparia riparia 51-100i
Saxicola rubetra 51-100i
Saxicola torquata 11-50i 101-250i
Scolopax rusticola 1-5i 1-5i
i = individuals; p = pairs.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Population
Migratory
Name Resident Breed Winter Stage
Serinus serinus 1-5p 11-50i 251-500i
Stercorarius parasiticus 6-10i
Stercorarius pomarinus 1-5i
Sterna bengalensis 1-5i
Sterna maxima 1-5i
Sturnus vulgaris 1001-10000i P
Sylvia atricapilla 251-500p 501-1000i 1001-10000i
Sylvia borin 501-1000i
Sylvia cantillans 101-250i
Sylvia communis 101-250i
Sylvia conspicillata 6-10i
Sylvia hortensis 51-100i
Sylvia melanocephala 251-500p P
Sula bassana 101-250i 1001-10000i
Turdus iliacus 11-50i
Turdus merula 251-500p
Turdus philomelos 51-100i 501-1000i
Turdus torquatus 11-50i
Turdus viscivorus 1-5i 1-5i
Upupa epops 51-100i
i = individuals; p = pairs.
Regularly occurring migratory species not listed in Annex I of the Birds Directive require the Member
States to adopt similar measures to Annex I species, bearing in mind the need for protection in the geographical
maritime and terrestrial area where this Directive applies, as regards their breeding, wintering and
moulting areas, and staging posts along their migratory routes.
The Bonn Convention.
Convention on the Conservation of Migratory Species.
The Bonn Convention, also known as the Convention on the Conservation of Migratory Species of Wild
Animals (or CMS) aims to conserve terrestrial, marine and avian migratory species throughout their range.
It was concluded on the 1 November 1983 under the auspices of the United Nations Environment
Programme, and is concerned with the conservation of wildlife and habitats on a global scale.
The objective of this Convention is the conservation of migratory species of wildlife worldwide. The parties
to the Convention are required to pay special attention to species whose conservation status is
unfavourable, and has to endeavour to apply the following main provisions.
The Bonn Convention or The Convention on the Conservation of Migratory Species of
Wild Animals (CMS). Main provisions.
• to promote, cooperate in or support research relating to migratory species.
• to provide immediate protection to migratory species included in Appendix I
• to conclude agreements covering the conservation and management of migratory
species listed in Appendix II
• to conserve or restore the habitats of endangered species.
• to prevent, remove, compensate for or minimise the adverse effects of activities or obstacles
that impede the migration of the species.
• to the extent feasible and appropriate, to prevent, reduce or control factors that are
endangering or are likely to further endanger the species.

Appendix I of the Convention includes a list of Migratory species which are endangered in Europe.
Appendix 2 lists migratory species which have an unfavourable conservation status and which require international
agreements for their conservation and management, as well as those which have a conservation
status which would significantly benefit from the international cooperation that could be achieved by an
international agreement.
Species recorded in Gibraltar and classified under Appendix I and II of the CMS are listed in the following
tables.
Table 5: Migratory species of wild animals, recorded in Gibraltar that are
included in Appendix I of the Bonn Convention.
Birds Spotted Eagle Aquila clanga
Spanish Imperial Eagle Aquila adalberti
Lesser Kestrel Falco naumanni
Audouin's Gull Larus audouinii
Reptiles Atlantic Green Turtle Chelonia mydas
Loggerhead Turtle Caretta caretta
Leatherback Turtle Dermochelys coriacea
Fish White Shark Carcharodon carcharias
Table 6: Migratory species of wild animals recorded in Gibraltar that are
included in Appendix II of the Bonn Convention.
Mammals Horseshoe Bats Rhinolophidae spp.
Mouse-eared Bat Myotis myotis
Soprano Pipistrelle Pipistrellus pygmaeus
Schreiber's Bat Miniopterus schreibersii
European Free-tailed Bat Tadarida teniotis
Sperm Whale Physeter macrocephalus
Bottle-nosed Dolphin Tursiops truncatus
Striped Dolphin Stenella coeruleoalba
Common Dolphin Delphinus delphis
Killer Whale Orcinus orca
Birds Red-throated Diver Gavia stellata
Great Northern Diver Gavia immer immer
Black-necked Grebe Podiceps auritus
Black Stork Ciconia nigra
White Stork Ciconia ciconia
Glossy Ibis Plegadis falcinellus
Greater Flamingo Phoenicopterus roseus
Grey Lag Goose Anser anser
Shelduck Tadorna tadorna
Wigeon Anas penelope
Shoveler Anas platyrhynchos
Gadwall Anas strepera
Pintail Anas acuta
Teal Anas crecca
Garganey Anas querquedula
Common Scoter Melanitta nigra
Red-breasted Merganser Mergus serrator
Honey Buzzard Pernis apivorus
Black-shouldered Kite Elanus caeruleus
Black Kite Milvus migrans
Red Kite Milvus milvus
Lammergeier Gypaetus barbatus
Egyptian Vulture Neophron percnopterus
Griffon Vulture Gyps fulvus
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Black Vulture Aegypius monachus
Short-toed Eagle Circaetus gallicus
Marsh Harrier Circus aeruginosus
Hen Harrier Circus cyaneus
Pallid Harrier Circus macrourus
Montagu's Harrier Circus pygargus
Goshawk Accipiter gentilis
Sparrowhawk Accipiter nisus
Buzzard Buteo buteo
Long-legged Buzzard Buteo rufinus
Lesser-spotted Eagle Aquila pomarina
Spotted Eagle Aquila clanga
Spanish Imperial Eagle Aquila adalberti
Golden Eagle Aquila chrysaetos
Booted Eagle Aquila pennata
Bonelli's Eagle Aquila fasciata
Osprey Pandion haliaetus
Lesser Kestrel Falco naumanni
Common Kestrel Falco tinnunculus
Merlin Falco columbarius
Hobby Falco subbuteo
Eleonora's Falcon Falco eleonorae
Lanner Falco biarmicus
Peregrine Falco peregrinus
Quail Coturnix coturnix coturnix
Common Crane Grus grus
Great Bustard Otis tarda
Black-winged Stilt Himantopus himantopus
Avocet Recurvirostra avosetta
Stone Curlew Burhinus oedicnemus
Collared Pratincole Glareola pratincola
Ringed Plover Charadrius dubius
Little-ringed Plover Charadrius hiaticula
Kentish Plover Charadrius alexandrinus
Golden Plover Pluvalis apricaria
Grey Plover Pluvalis squatarola
Woodcock Scolopax rusticola
Mediterranean Gull Larus melanocephalus
Slender-billed Gull Larus genei
Audouin's Gull Larus audouinii
Gull-billed Tern Sterna nilotica nilotica
Caspian tern Sterna caspia
Royal tern Sterna maxima albidorsalis
Lesser-crested tern Sterna bengalensis
Sandwich Tern Sterna sandvicensis
Roseate tern Sterna dougalii
Little tern Sterna albifrons
Black Tern Chlidonias niger
White-winged Tern Chlidonias leucopterus
Turtle Dove Streptopelia turtur turtur
European Bee-eater Merops apiaster
European Roller Coracias garrulus
Pied Flycatcher Ficedula hypoleuca
Red-breasted Flycatcher Ficedula parva
Spotted Flycatcher Muscicapa striata
Reptiles Loggerhead Turtle Caretta caretta caretta
Atlantic Green Turtle Chelonia mydas mydas
Leatherback Turtle Dermochelys coriacea coriacea
Fish White Shark Carcharodon carcharias
Insects Monarch Butterfly Danaus plexippus

EUROBATS
Bats have few natural enemies but many species are under threat from the way man has exploited and
changed their natural habitats. Many of their traditional roost and breeding sites have been disturbed and
lost and their feeding areas have been severely reduced. The degradation of the countryside and the
exploitation of the forest and woodland areas, together with the uncontrolled use of pesticides, have resulted
in bats being amongst the animals that have suffered most in recent times. Worldwide there are approximately
1,100 species of bats, many of which are endangered. This represents approximately 25% of all
mammalian species on Earth.
EUROBAT entered into force on 16 January 1994. It was set up as part of the Bonn Convention and
concluded under ‘The Convention on the Conservation of Migratory Species of Wild Animals’ and specifically
under ‘The Agreement on the Conservation of Bats in Europe (1994). This agreement recognises that
endangered migratory species can only be properly protected if activities are carried out over their entire
migratory ranges. The EUROBATS Agreement area covers 48 Range States in Europe. The geographical
area stretches from Northern Scandinavia to the Mediterranean Sea and from the Atlantic Ocean to the Ural
Mountains. The aims of the Bat Agreement are to protect all European populations of 45 bat species -
whether migratory or not - occurring in Europe and non-European Range States: through legislation, education,
conservation measures and international cooperation with Agreement members and with those who
have not yet joined. The Agreement sets up legal protection standards, while developing and promoting
transboundary conservation and management strategies, research and public awareness across the
Agreement area. It also assists in finding financial support for mainly cross-border oriented projects and has
developed a wide-ranging Conservation and Management Plan, which is the key instrument for the
Agreement’s implementation. It addresses such issues as legal requirements, population survey and monitoring,
roosts, foraging habitats, the use of pesticides and the promotion of public and professional awareness.
This is one of the Multilateral Environment Agreements that applies to Gibraltar.
ACCOBAMS
Agreement on the Conservation of Cetaceans of the Black Sea,
Mediterranean Sea and contiguous Atlantic area.
The Convention on the Conservation of Migratory Species of Wild Animals (CMS), adopted this agreement
as a regional approach for cetacean conservation in the Mediterranean and Black Seas. The agreement
entered into force on 1 June 2001, and Gibraltar is obliged conform to the objectives.
ACCOBAMS covers all cetaceans that have a range within the geographical area of the Agreement and
that enter it accidentally or occasionally. The area covered includes the Black Sea, Mediterranean Sea and
Atlantic coasts of Morocco, Southern Spain and Portugal.
The Agreement aims to reduce threats to all cetaceans in these waters and to promote closer cooperation
amongst Parties with a view to conserving all cetacean species present in the area. It also calls on
its members to enforce legislation and to prevent the deliberate taking of cetaceans in fisheries by vessels
under their flag or within their jurisdiction, and to minimise incidental catches.
Gibraltar has incorporated legislation for the protection and conservation of cetaceans within the Nature
Protection Ordinance LN 1991/11, and within the Marine Nature Reserve Regulations 1995 LN 1995/143.
Unfortunately the latter legislation has never been enforced and the illegal use of nets could lead to incidental
catches of cetaceans.
Land reclamation and industrialisation of the coastal waters around Gibraltar, and the increase in maritime
traffic are placing severe pressure on our resident and migratory populations of cetaceans.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Bern Convention.
Convention on the Conservation of
European Wildlife and Natural Habitats.
The Bern Convention is a binding international legal instrument in the field of Nature Conservation,
which covers the whole of the natural heritage of Europe and extends to some African States.
Adopted and signed in Bern in September 1979 the Convention came into force on 1 June 1982, with
the aim of conserving wild flora and fauna and their natural habitats and to promote European cooperation
in that field. It includes the European Community, 40 member states of the Council of Europe and Morocco,
Senegal, Tunisia and Burkina Faso.
The Convention is a fundamental treaty at European level for biological diversity, and was included within
the EC under Council Decision 82/72/EEC of 3 rd December 1981. Gibraltar is obliged to apply the objectives
in the Convention, in conjunction with the member state, the United Kingdom.
The parties undertake to:
• Promote national policies for the conservation of wild flora, wild fauna and natural habitats;
• Integrate the conservation of wild flora and fauna into national planning, development and environmental
policies;
• Promote education and disseminate information on the need to conserve species of wild flora and
fauna and their habitats.
The Convention lists protected species in four Appendices: Appendix I: strictly protected flora species,
Appendix II: strictly protected fauna species, Appendix III: protected fauna species, and Appendix IV: prohibited
means and methods of killing, capture and other forms of exploitation.
Appropriate legislative and administrative measures must also be adopted to conserve the wild fauna
species listed in Bern Appendix II. The following are prohibited:
• All forms of deliberate capture and keeping and deliberate killing.
• The deliberate damage to or destruction of breeding or resting sites.
• The deliberate disturbance of wild fauna, particularly during the period of breeding , rearing and hibernation.
• The deliberate destruction or taking of eggs from the wild or keeping these eggs
• The possession of and internal trade in these animals, alive or dead, including stuffed animals and any
part or derivative thereof.
Any exploitation of wild fauna specified in Bern Appendix III must be regulated, and the Convention provides
exceptions from the above provisions:
• For the protection of flora and fauna
• To prevent serious damage to crops, livestock, forests, fisheries, water and other forms of property.
• In the interest of public health and safety, air safety or other overriding public interests.
• For the purposes of scientific research and education, of repopulation, of reintroduction and for the
necessary breeding.
• To permit, under strict supervised conditions, the taking, keeping or other judicious exploitation of certain
wild animals and plants in small numbers.
Gibraltar undertook the legislative and regulatory measures through the introduction of nature protection
and conservation laws. This was done with the voluntary cooperation of GONHS, who incorporated all
legislative requirements and exceptions within these laws.
Amongst the laws dealing with nature protection and conservation are the:
• Endangered Species Ordinance 1990 Ord. Nº. 1990-54
• Nature Protection Ordinance 1991 Ord. Nº. 1991-11
• Nature Conservation Area(Upper Rock) Designation Order 1991 LN 1993/51
• Nature Conservation Area (Upper Rock Nature Reserve) (Protection and Regulation) Regulations
1993 LN 1993/52

• Marine Nature Reserve Regulations 1995 LN 1995/143
• Control of Trade in Endangered Species Ordinance1998 Ord. Nº. 1991-11
• Keeping of Wild Animals Ordinance 2002 Ord. Nº. 2002-25
The International Context
Gibraltar Government still has to formalise national policies for the main objectives of the Convention,
especially for the conservation of wild flora, wild fauna and natural habitats, and the integration of the conservation
of wildlife into national planning, development and environmental policies.
Table 7: Other important species of flora and fauna.
Group Scientific Name Motivation
M R I P
X Patella ferruginea R C
X Lithophaga lithophaga R C
X Pinna nobilis V C
X Nudibranchia spp. C-V B
X Balaenoptera acutorostrata V C
X Balaenoptera physalus V C
X Delphinus delphis C-V C
X Globicephala macrorhynchus R C
X Globicephala malaena R C
X Grampus griseus V C
X Orcinus orca V C
X Physeter catodon V C
X Stenella coeruleoalba C-V C
X Tursiops truncatus R C
X Chelonia mydas R C
X Dermochelys coriacea V C
X Silene tomentosa 1 B
X Ononis natrix var. ramosissima 251-500 B
X Saxifraga globulifera 101-250 B
X Thymus wildenowii 101-250 B
X Iberis gibraltarica 1001-10000 A
X Limonium emarginatum 1001-10000 A
X Cerastium gibraltaricum 251-500 B
X Macaca sylvanus 101-250 D
X Tadarida teniotis R C
B= birds
M= mammals
A= amphibians
R= reptiles
F= fish
I= invertebrates
P= plants
X Hemidactylus turcicus V A
X Coluber hippocrepis C C
X Chalcides bedriagai V C
X Macrothele calpeiana R C
X Cecilioides spp. R B
X Zygaena fausta gibraltarica C B
X Buprestis (Yamina) sanguinea R B
X Laemostenus(Ceuthostenus)
mauretanicus ssp. polymephus
R A
X Alphasida (Betasida) argentolimbata R A
C=common
R=rare
V=very rare
A. National Red Data list
B. Endemics
C. International Conventions (incl. Bern, Bonn and Biodiversity)
D. Other reasons
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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CITES
The Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES or the
Washington Convention), was drafted as a result of a resolution adopted in 1963 at a meeting of members
of IUCN (The World Conservation Union). The text of the agreement was adopted by 80 countries in
Washington DC, USA, in March 1973 and came into force in July 1975. As of September 2003 there were
163 Contracting Parties to the Convention.
CITES is an International agreement that aims to regulate the international trade in species that are
endangered or may become endangered by their uncontrolled exploitation. Species covered in the
Convention are listed in the three Appendices according to the degree of protection each requires. The
European implementation of CITES is applied through Regulation 338/97 EC and Regulation 1808/01 EC,
and is more rigorous than that required by the Convention in that they include several non CITES species,
and contain provisions to prohibit and restrict the import of species that are considered to be a threat to the
European native flora and fauna.
In Gibraltar, all species that are covered by Articles I, II and III of the CITES Convention are controlled
by the Gibraltar authorities and monitored by the Gibraltar Scientific Authority. Importation or exportation
of species included in the Convention is only permitted with the relevant authority of CITES documentation.
Species of native flora and fauna, including migratory species that are listed under CITES are included in
Gibraltar legislation under the Endangered Species Ordinance 1990-54 and the Control of Trade in
Endangered Species Ordinance 1998 (LN 1998-11).
World Heritage Convention
This convention was adopted in France in 1972, came into force in December 1975 and was known as
‘The Convention Concerning the protection of the World Cultural and Natural Heritage’; in short The ‘World
Heritage Convention’. The United Kingdom ratified the Convention in May 1984.
This Convention is a unique international instrument that seeks to protect both cultural and natural heritage.
Entities that can be considered for incorporation into the World Heritage list are:
• Ancient monuments
• Museums
• Biodiversity sites
• Geological heritage sites
It is also important to recognise landscapes that combine these values even though many of the World
Heritage Sites fall into the cultural or natural categories, especially so where the physical and biological
aspects of landscape have progressed alongside human activity.
As a result of Gibraltar’s wealth in cultural heritage a bid for the inclusion of the Territory of Gibraltar for
World Heritage Status was submitted with draft management plans to the member state, the United
Kingdom that would be included with other bids from other Overseas Territories and those of the UK.
On the 6 March 2006 the Gibraltar Government withdrew this bid on the basis that it would undermine
the capability of economic and development growth of the territory. It stated that future bids would be specific
to historical heritage e.g. Moorish Castle, City Walls etc.
EC Habitats Directive.
The EC Directive on the Conservation of Natural Habitats
and of Wild Flora and Fauna.
The Habitats Directive 92/43/EEC 1992, identifies habitats and species of special interest within the
European Community, and legislates for the notification of Special Areas of Conservation (SACs). The
Directive (92/43/EEC) requires Member States to designate certain sites as SACs. From these national
lists, Member States and the Commission will agree the Sites of Community Importance, which will become
designated SACs. The UK forwarded 331 sites to Brussels as Sites of Community Importance or

Candidate Special Areas of Conservation (cSACs). Together with Special Protection Areas classified under
the Council Directive on the conservation of wild birds (79/409/EEC), SACs will constitute the European
Union's Natura 2000 network.
The Habitats Directive was transposed into Gibraltar law on 25 th August 1995 (Nature Protection
Ordinance 1991 (Amendment) Regulations 1995) as its obligation as part of the member state. Proposed
candidate Special Areas of Conservation (cSACs) were submitted for their designation to the EC in late
2005. Information regarding the status of species of wild flora and fauna was compiled by GONHS and
presented to the Gibraltar Government. It is being assembled by the Joint Nature Conservation Committee
(JNCC), in the United Kingdom as part of the responsibility of the Member State. The lists of all requirements
and factors affecting Gibraltar that was requested by the JNCC, and affect the implementation of the
Directive, are given below (Tables 5, 6 and 9 and Figures 1 and 2).
The sites now require full designation into the European Union’s Natura 2000 network. The designation
of the marine site is being held back by the Kingdom of Spain who disputes the right of Gibraltar to
claim territorial waters, despite being a signatory to the Treaty of Rome and the Geneva Convention.
Table 8: Terrestrial & marine mammals reptiles & amphibians listed in
Annex II of the Habitats Directive 92/43/EEC.
The Natura 2000 Network
The Natura 2000 Network is a network of protected areas set up under European Council Directive
79/409/EEC on the conservation of wild birds and Council Directive 92/43/EEC on the conservation of natural
habitats and of wild fauna and flora. Member States are required to set up procedures that will enable
the establishment of a Europe wide network of protected areas that will guarantee the survival of threatened
plants, animals and habitats.
Gibraltar has complied
with the requirements
of Natura 2000
by designating several
terrestrial and one
marine site as cSACs
under the Habitats
Directive that will fulfil
these needs (Figures 1
& 2).
Name Resident
Population
Migratory
Breeding Winter Stage
Miniopterus schreibersi 101-250i
Myotis myotis 11-50i
Tursiops truncatus 6-10i
Careta careta V
i = individuals; p = pairs. C= Common; R= Rare; V= Very rare.
Figure 1: Terrestrial candidate
Special Areas of Conservation in
green.
Figure 2: Marine candidate
Special Area of Conservation in
blue within British territorial waters
around Gibraltar.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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The Rio de Janeiro Convention on Biological Diversity
This is better known as the ‘Biodiversity Convention’. It seeks to prevent and reduce the loss of biological
diversity at source because of its intrinsic value and its ecological, genetic, social, economic, scientific,
educational, cultural, recreational and aesthetic value, and seeks to promote cooperation among States
and Intergovernmental Organisations.
The Convention on Biological Diversity was signed by Member States at the United Nations Conference
on Environment and Development in Rio de Janeiro. The decision approves the Convention on behalf of
the European Community, who concluded the CBD in Council Decision 93/626/EEC on 25 October 1993.
The main provisions required under the Convention are to:
• Conserve biological diversity.
• Ensure the sustainable use of this diversity.
• Share the benefits generated by the use of genetic resources.
• Ensure access to genetic resources and relevant technologies.
This is especially significant to Gibraltar where there may be a conflict of interest regarding the designation
of the Marine Reserve Special Area of Conservation under the Habitats Directive, where Spain traditionally
does not recognise British territorial waters around Gibraltar. Nevertheless each contracting party
must, as far as possible, cooperate with other Contracting Parties directly or, where appropriate, through
competent international organisations both in respect of areas beyond national jurisdiction and on other
matters of mutual interest, for the conservation and sustainable use of biological diversity.
Gibraltar must in accordance with its particular conditions and capabilities:
• Develop national strategies, plans or programmes for the sustainable use of biological diversity or
adapt for this purpose, existing plans or programmes.
• Integrate, as far as possible and as appropriate, the conservation and sustainable use of biological
diversity into relevant sectoral and cross-sectoral plans, programmes and policies.
This is partly achieved through the development of the species, alien species, habitat and site action
plans and the programmes recommended within this document. Further research and monitoring will be
required to ensure the success of each plan and programme, and to develop further strategies to ensure
the conservation and sustainable use of our biodiversity.
Each contracting party should as far as possible:
• Identify components of biological diversity important for its conservation and sustainable use, having
regard to the indicative list of categories set out in Annex I.
• Monitor, through sampling and other techniques, the components of biological diversity identified, paying
particular attention to those requiring urgent conservation measures and those that offer the greatest
potential for sustainable use.
• Identify processes and categories of activities which have or are likely to have significant adverse
impacts on the conservation and sustainable use of biological diversity and monitor their effects
through sampling and other techniques.
• Maintain and organise, by any mechanism, data derived from identification and monitoring activities
pursuant to the points set out above.
These particular provisions have been and are being tackled on a voluntary basis by GONHS experts.
Botanical, invertebrate and vertebrate surveys and population studies, monitoring and research programmes,
and other activities including the establishment of the Gibraltar Biodiversity Project that are generating
interesting scientific data, are addressing some of these provisions. Nevertheless there is a need
for the local authorities to recognise and support this work by capacity building, equipping and funding
these projects and activities that will ultimately benefit the conservation and sustainable use of biological
diversity in Gibraltar.
Each contracting party should adopt economically and socially sound measures that act as incentives

for the conservation and sustainable use of the components of biological diversity by:
• Establishing and maintaining programmes for scientific and technical education and training for the
identification, conservation and sustainable use of biological diversity and its components and providing
support for such education and training for the specific needs of developing countries.
• Encouraging research which contributes to the conservation and sustainable use of biological diversity,
particularly in developing countries.
• Promoting the use of scientific advances in biological diversity research in developing methods for
conservation and sustainable use of biological resources.
It is therefore essential that the Gibraltar Government actively supports, with infrastructural and economic
initiatives, the GONHS programmes and activities that are addressing the provisions required under
the Convention on Biological Diversity.
Public participation should be promoted and enhanced by highlighting the importance of biological
diversity through the media and including these topics in educational programmes.
GONHS is currently working on educational material that will promote awareness on our biodiversity in
middle schools. Already there has been a positive response from the Education Department who are willing
to support and disseminate the literature amongst the schools. The poster produced in November 2005
by GONHS to promote Gibraltar’s Biodiversity was also well received and has also been circulated by the
education authorities as well.
Several initiatives of the Biodiversity Convention do not strictly apply to Gibraltar. Amongst these are
the ‘use and sustainable use and benefits of genetic resources’ that mainly apply to countries that are agricultural
producers of crops and livestock and engage in aquiculture or commercial fisheries, where the benefits
of specific disease resistant flora or fauna would be of significant value to developing countries.
The Biodiversity Convention includes other articles that also apply in part or in full to Gibraltar:
Cartagena Protocol on Biosafety.
A Council Decision 2002/628/EC concerns the conclusion of the Cartagena Protocol on Biosafety
(Official Journal L 201 31 st July 2002). The aim is to ensure that the transfer, handling and use of living
organisms resulting from modern biotechnology do not have adverse effects on biological diversity or
human health, while specifically focusing on transboundary movements.
Gibraltar must be very careful not to accidentally or unwittingly allow its territory, outside the External
Frontiers Convention, to be used as a convenient gateway into Europe or any other country, in any transboundary
movements that will breach the provisions of the Cartagena Protocol on Biosafety.
Alien Species.
Article 8 (h) of the Convention on Biological Diversity (CBD) requires the contracting parties, as far as
possible and as appropriate, to prevent the introduction of alien species, and to control or eradicate those
alien species which threaten ecosystems, habitats or species. The CBD is developing agreed global procedures
and guidelines, in collaboration with the Global Invasive Species Programme (GISP) that will cover
the effective regulation of the introduction, control and eradication of alien species which are or may cause
environmental problems.
In Gibraltar, importation of animal species only requires a health certificate from the Environmental
Agency and in the case of CITES listed species, a licence from the Gibraltar Management Authority (currently
the Collector of Customs) on the advice of the Scientific Authority. The importation of plant species
does not require a phyto-sanitary certificate from the Environmental Agency since Gibraltar has no agriculture.
However, plants covered by CITES should be subjected to the same procedures as animals.
Nevertheless, there are no legal measures to control the importation and introduction of alien pests and
pathogens. In the UK, the Department for Environment, Food and Rural Affairs (Defra), undertook a major
review of alien species policy, including a review of legislation and guidance, whose recommendations were
published in March 2003. Gibraltar should do likewise and model legislation and guidelines around the
UK’s alien species policy and apply this to Gibraltar’s requirements that must include legal provisions relat-
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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ing to the control and eradication of alien species and include important introduction vectors e.g. ballast
water discharge (see Marine Habitats).
Biodiversity and Tourism.
Tourism is one of the fastest-growing industries as well as a major source of foreign exchange earning
and employment for many developing countries. It has the potential to contribute in a positive manner to
socioeconomic advancement, but the fast and sometimes uncontrolled growth of tourism can be a major
cause of environmental degradation and loss of local identity and traditional cultures. Biological and physical
resources are in fact the assets that attract the tourists. However, the stress imposed by tourism activities
on fragile ecosystems accelerates and aggravates their depletion. The CBD has developed guidelines
for sustainable planning and management of tourism activities in vulnerable ecosystems and habitats of
major biodiversity importance.
Gibraltar receives in excess of 7.5 million visitors a year of which a large percentage visit the Upper
Rock Nature Reserve. There are no limitations imposed on the number of visitors and vehicles that access
the Nature Reserve and numbers are growing annually. This imposes an unsustainable strain on the
ecosystem and its flagship species, the Barbary Macaque, which is suffering from undue stress and unacceptable
direct interaction with visitors, encouraged by some tour guides and other operators. Other
species of plants and animals and their habitats are also experiencing the adverse effects of noise and
atmospheric pollution and very little is being done to minimise or mitigate these factors (Perez & Bensusan
2005). Similarly the artificial reef is receiving uncontrolled numbers of scuba divers that may adversely
affect the main reason for having the reef there in the first place; that is to increase biodiversity.
Climate Change and Biodiversity.
Collaboration is active between the Conference of Parties of the CBD and the United Nations
Framework Convention on Climate Change UNFCCC. Measures for the conservation of forests and other
ecosystems can contribute simultaneously to the objectives of both organisations where there is a need to
reduce the rate of climate change to allow ecosystems to adjust. The impact on biological diversity that climate
changes can have is immense with temperature increases, sea-level rise, changes in precipitation
and extreme climatic events amongst the main cause for concern.
There is a need for GONHS to work with Government’s Ministry for the Environment on the implications
of climate change for nature conservation and the natural environment in Gibraltar. This requires a programme
to investigate the likely future impacts of climate change to species and habitats over the next 50
years including its possible effects on the marine environment. It will require policy debate and a legislative
framework to accommodate and mitigate impacts on nature conservation.
Needless to say, the impact of climate change on the integrity and the economy of Gibraltar could be
catastrophic. It only requires a 2m rise in sea-level to isolate the Rock of Gibraltar from the mainland, and
sever our terrestrial and aviation links with the outside world.
Ecosystem Approach.
The ecosystem approach is one of the underpinning philosophies of the Convention on Biological
Diversity (CBD) and was adopted at the second Conference of Parties (CoP2) as the primary framework
for action. This approach is the strategy for the integrated management of land, water and living resources
that promotes conservation and sustainable use in an equitable way. It is based on the application of
appropriate scientific methodologies focused on levels of biological organisation, which encompasses the
essential processes, functions and interactions among organisms and their environment.
The ecosystem approach has not been applied entirely to Gibraltar as there has never been the occasion
where this initiative could be applied. Nevertheless, the Upper Rock Nature Reserve, together with its
management and action plan (Perez & Bensusan, 2005), that addresses the needs of this defined physical
area, is perhaps the closest example where an ecosystem approach has in part been applied, encompassing
the requirements of the wildlife within that environment.

Global Strategy for Plant Conservation.
A Global Strategy for Plant Conservation was adopted at the sixth meeting of the Conference of Parties.
This included 14 outcome-oriented global targets for 2010 that support the broad objectives of:
• understanding and documenting plant diversity.
• conserving plant diversity.
• using plant diversity sustainably.
• promoting education and awareness about plant diversity.
• building capacity for the conservation of plant diversity.
The strategy should operate as a flexible framework within which national and/or regional targets may
be developed and a pilot approach for the use of outcome targets under the CBD within the context of the
Strategic Plan.
The Gibraltar implementation of the objectives of this strategy is being undertaken, again on a voluntary
basis, by GONHS in collaboration with the Gibraltar Botanic Gardens. This initiative is being assisted
through the cooperation of the Royal Botanic Gardens, in Kew. The Gibraltar Government should invest in
capacity building, equipping and supporting this and other strategies under their obligation to implement the
CBD.
Global Taxonomy Initiative
The Global Taxonomy Initiative was established by the Conference of Parties to address the lack of taxonomic
information and expertise in many parts of the world, and thereby to improve decision-making in
conservation, sustainable use and equitable sharing of the benefits derived from genetic resources. The
GTI is intended to support implementation of the work of the Convention on thematic and cross-cutting
issues.
The implementation of this strategy is being undertaken by GONHS under their ‘Gibraltar Biodiversity
Project’ that was launched in 2004, with the aim of cataloguing Gibraltar's living resources, producing habitat
and species action plans for their protection, re-establishing lost species and recreating lost habitats.
Again most of this is being done on a voluntary basis, except the action plans and habitat recommendations
within this document, which have been funded by the Overseas Territories Environment Programme.
Impact Assessment, Liability and Redress.
Article 14(1) of the CBD requires the Contracting Parties to ensure that proposed projects which are
likely to have significant adverse effects on biodiversity are the subject to Environmental Impact
Assessment (EIA) with a view to avoiding and minimising such effects. Article 14(2) requires the
Conference of Parties to examine the issue of liability and redress, including restoration and compensation,
for cross-border damage to biological diversity.
The Eco-Management and Audit Scheme (EMAS) is a voluntary scheme established under the
European Council Regulation 761/01 and aims to recognise and reward organisations that go beyond minimum
legal compliance and continuously improve their environmental performance.
Environmental Impact Assessments are covered by EU legislation (the 1985 Environmental
Assessment Directive). This was transposed into Gibraltar law under the ‘Town Planning (Environmental
Impact Assessment) Regulation 2000’ (LN 2000/013).
The authority who decides whether a project requires an EIA is the Town Planner who provides a
screening opinion to the Minister before planning permission is granted. The Minister then provides a
screening direction to the developer within 28 days that should be published in the Gazette. Nevertheless
the Minister may direct that a particular proposed development is exempt from the application of these regulations
in accordance with Article 2(3) of the Directive, and shall send a copy of any such direction to the
Development and Planning Commission (DPC). The Article in the Directive states that this should be done
in exceptional cases and in such cases should consider whether another form of assessment would be
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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appropriate and whether the information collected should be made available to the public. Notwithstanding
this, the Minister should make the information relating to the exemption and the reasons for granting it publicly
available. The legislation therefore bestows on the Town Planner and the Minister the power to reject,
in any but exceptional circumstances, the requirement for an EIA without proper public consultation, consideration
or explanation.
Transboundary impacts on biodiversity as a result of reclamation projects by both the Kingdom of Spain
and Gibraltar should be the subject of EIAs.
The Gibraltar Government should address the issues of liability and redress in the case of negative
impact on the environment, and legislate to provide and include mitigation measures within these regulations.
Indicators.
Biodiversity indicators should be promoted as a method of assessing the effectiveness of measures
taken to conserve biodiversity under the CBD. This issue, raised at the second Conference of Parties and
undertaken since the fourth Conference, has focused on identifying a core, global set of indicators which
incorporate state, pressure and response indicators.
Gibraltar implementation has not been put in practice but should, when conditions are right, include:
• The guidance and framework for indicators being discussed within the CBD.
• The efforts of the European Commission and the European Environmental Agency (EEA) to develop
criteria for the identification of indicators at the regional and national level.
• Gibraltar biodiversity strategies and the need for indicators that they identify.
• Reporting requirements (national and international).
• Ongoing monitoring and surveying activities.
GONHS has already developed a number of biodiversity monitoring, surveillance, and recording programmes
that include ornithological, botanical and invertebrate studies of the marine and terrestrial ecosystems.
These initiatives should continue to be encouraged and supported by the relevant authorities, by
capacity building, and financial support.
Protected Areas.
The Convention on Biological Diversity defines a protected area as ‘a geographically defined area which
is designated or regulated and managed to achieve specific conservation objectives.’ Article 8(a) of the
CBD requires Contracting Parties to establish a system of protected areas or areas where special measures
need to be taken to conserve biological diversity. Article 8(c) requires Parties to regulate or manage
biological resources (whether within or outside protected areas) with a view to ensuring their conservation
and sustainable use, while Article 8(d) aims to promote the protection of ecosystems, natural habitats and
species in natural surroundings. Article 8(f) requires the rehabilitation and restoration of degraded ecosystems
and the promotion of the recovery of threatened species. A system of protected areas forms a central
element of any national strategy to conserve biological diversity, and the central role of protected areas
has been repeatedly emphasised in decisions of the CoP.
In Gibraltar the implementation of protected areas is being achieved under the Habitats Directive with
the designation of candidate Special Areas of Conservation of the Upper Rock Nature Reserve, the Great
Sand Slopes and Talus slopes and the Windmill Hill Flats as the terrestrial areas and the designation of the
candidate marine Special Area of Conservation of the territorial waters that encompass the area south of
Sandy Bay around to the South end of the South Mole. This fulfils the obligations under the CBD, but allows
for other areas to be conserved outside the remit of the Habitats Directive, under the Nature Protection
Ordinance.
Public Awareness and Education.
Increasing the level of public awareness of, and support for, biodiversity is seen as essential in both the
short and long term for the Convention on Biological Diversity to succeed in achieving its aims. Article 13
of the CBD requires Contracting Parties to:

• Promote and encourage understanding of the importance of biodiversity, the measures required for its
conservation, and the inclusion of these topics in educational programmes
and
• co-operate with other States and international organisations in developing educational and public
awareness programmes with respect to the conservation and sustainable use of biodiversity.
Article 13 was addressed by the fourth Conference of Parties, where it was decided that public education
and awareness issues should become an integral component of all sectoral and thematic items under
the CBD’s works programme.
The raising of public awareness on biodiversity issues in Gibraltar is being tackled by GONHS, largely
through the media, through its publications, talks, seminars and through its membership. GONHS has published
several articles in the main Gibraltar daily newspaper ‘The Gibraltar Chronicle’, highlighting the work
being done as part of the Gibraltar Biodiversity Project, has held public presentations, talks and seminars
based on the work required under the CBD and is currently in contact with the Department of Education to
find ways in which information relating to the conservation of biodiversity can be made available to schools.
Sustainable use of Biodiversity.
Sustainable use of the components of biodiversity is one of the three objectives of the CBD, as defined
in Article 2 and elaborated in Article 10. The development of practical principles, operational guidance and
associated instruments, focusing on different ecosystems within the CBD’s thematic work programme, was
part of the objectives in three workshops that came about with the adoption of sustainable use of biodiversity
as a cross-cutting issue at the fifth Conference of Parties.
The Gibraltar Government must address all the issues encompassed within the Convention on
Biological Diversity and compile a biodiversity strategy where they tackle sustainable development. There
is a growing realisation that the current model of development is unsustainable. In other words we are living
beyond our means and beyond our capability to accommodate development within the natural environment.
The Gibraltar Government must realise that there are serious constraints and limitations as to how
far Gibraltar can continue to develop and that we are reaching saturation point, that will affect the ability to
provide jobs, accommodation, infrastructure and the quality of life that we all yearn for. Our environment
and natural resources are being placed under increasing stress that will affect our welfare and livelihoods.
We need to strive for a 'development which meets the needs of the present without compromising the
ability of future generations to meet their own needs'. This is the widely recognised international concept
of sustainable development and unless we start to make real progress toward reconciling these contradictions,
we all, wherever we live, face a future that is less certain and less secure than we in Gibraltar have
enjoyed over the past fifty years. Prosperity and development do not necessarily mean a better future or a
better quality of life. We need to make a decisive move toward more sustainable development both
because it is the right thing to do - and because it is in our own long-term best interests. It offers the best
hope for securing the future.
2010 Biodiversity Target
The Conference of Parties adopted a strategic plan for the Convention on Biological Diversity. Its mission
statement commits the Parties to achieve by 2010 a significant reduction of the current rate of biodiversity
loss at the global, regional and national level as a contribution to poverty alleviation and to the benefit
of all life on earth.
This target was subsequently endorsed by the World Summit on Sustainable Development.
The objectives of the meeting on ‘2010 Global Biodiversity Challenge’ held in May 2003 were:
• To review approaches for understanding and measuring biodiversity loss;
• To review the 2010 target in the context of other biodiversity-related targets
• To identify key initiatives in addressing biodiversity loss (such as MEAs) and how they relate to the
2010 target; and
• To review and agree on the most appropriate approaches for reporting on progress.
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3. Key Species & Habitats

Biodiversity Action Plan, Gibraltar: Planning for Nature
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3. Key Species & Habitats
The conservation of species and habitats in Gibraltar requires an intimate knowledge of the wildlife of
the Rock and its interrelationship with its environment, together with an appreciation of its needs and an
understanding of potential and existing threats.
Large countries have benefited from having numerous scientists with ample resources and a wealth of
knowledge, with large biological datasets. This has facilitated the preparation of biodiversity action plans,
as most of the groundwork required was available in national databases. This is not the case in small countries
or territories, such as Gibraltar, where much of the groundwork in some taxonomic groups is still
incomplete and requires further research. Nevertheless a great deal of work has been accomplished in the
last thirty years – largely by GONHS through the efforts of its volunteers – and this has resulted in a thorough
knowledge of much of the flora and fauna and their habitats. Despite this the development of action
plans has required further monitoring and surveying of both species and habitats in order to assess the condition
of habitats, the distribution and welfare of species and the potential and existing threats that affect
both.
Our knowledge of the wildlife in Gibraltar in historic times is limited, although we are indebted to a number
of amateur naturalists, whose publications provide a diversity of useful references. We know of the
immense loss and transformation of the natural vegetation of the Rock, the growth of the population and of
urban areas and of the expansion of the port and harbour. However, we lack intimate knowledge of some
of the wildlife present before this transformation and are not aware of all of the species which may have
become extinct locally.
Wildlife conservation is most often carried out through the management and protection of habitats.
However, some species require their own action plans due to their particular habitat requirements, because
their distribution is restricted globally or locally, or because they are threatened with local extinction.
Two types of conservation action plans have been adopted here. These are the Habitat or Site Action
Plans and the Species Action Plan. All sites considered important in biodiversity terms have been included.
The criteria used in selecting the species for independent action plans are as follows:
• Endemic or near-endemic species, subspecies or varieties
• Species with a restricted global distribution
• Species with a restricted regional and/or local distribution
• Species included in the EU Birds or Habitats Directive; the Bern, Bonn, or CITES Conventions or protected
by the Nature Protection Ordinance (L/N 13 1991)
• Species that are not endangered internationally and are not rare in nearby Spain, but which are rare
and threatened in Gibraltar
Each species has been classified under one of four categories of conservation concern (Table 1).
Priority species of conservation concern are listed in appendix 1, together with their categories and the sites
and habitats in which they are found.
Table 1: Categories of Conservation Concern assigned to species included in the Action Plans.
Category Definition
Global The presence of the species in Gibraltar is important to its international
conservation, due to a) Gibraltar forming all or a large part of its distribution or
harbouring all or much of its population, or b) the species having an overall
unfavourable conservation status worldwide
European The presence of this species in Gibraltar is important to its conservation in
Europe because a) populations of the species in Gibraltar form an important
component of the overall European population, or b) the species has an
unfavourable conservation status throughout the whole of Europe
Regional The species is not threatened at an International level but is rare or absent in
neighbouring Andalucía
Local The species is not uncommon in neighbouring Spain but has an unfavourable
conservation status in Gibraltar
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Figs 1 and 2 give the proportions of priority vascular plant and vertebrate species within each of our four
categories. A similar figure has not been prepared for invertebrates as only a small number of species have
been considered and the presence of all of these in Gibraltar is deemed to be of global importance.
Figure 1: Relative importance of vascular plant species included in the action plans.
Figure 2: Relative importance of vertebrate species included in the action plans
In preparing Action Plans for sites and habitats, it is important to consider the number of priority species
that each of these holds, as well as the category of importance that these species are given. Figs. 3 and
4 show the number of priority vascular plant and vertebrate species of each category found at each site.

Figure 3: Number and relative importance of priority vascular plant species per site.
Figure 4: The number and relative importance of priority vertebrate species per site.
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It can be seen from Figs. 3 and 4 that sites differ in their importance to priority species. The Upper Rock
holds the largest number of priority plant and vertebrate species. It also holds the largest number of
species that are of global and European importance. The importance of the open areas of the Upper Rock
– which cover a relatively small area of the Nature Reserve – to the Upper Rock’s overall biodiversity is
clear.
Sites that hold relatively few species should not necessarily be considered less important in the conservation
of biodiversity. Sites that hold relatively few priority species may hold species that no other sites
hold, and this may reflect the difference in habitat between these sites and others. This highlights the fact
that, as well as the number of priority species at each site, the identity of these species also needs to be
considered in site conservation planning. Fig. 6 shows, for each site, the number of species only found at
one of them.
Figure 5: Number of priority species found at one site alone, for each site.
The importance of each site to biodiversity partly reflects their area. This may be due to a variety of factors.
Firstly, the Species-Area effect determines that larger areas hold more species, partly because larger
areas can hold larger, more stable populations (Begon et al. 1996). Also, a larger site is more likely to
hold a higher diversity of habitats.
A more precise appraisal of the relative importance of sites to priority species can be gathered by examining
the importance of habitat types to our endangered or vulnerable fauna and flora. Many sites consist
of more than one habitat. It is likely that many of the sites that hold a large number of priority species also
hold several habitats, and that the diversity of priority species found at these sites in part reflects habitat
diversity. However, it is clear that some habitats are more important than others for priority species. The
relative importance of different habitats to priority species is shown in figs. 6 and 7. In addition, fig. 8 shows,
per habitat the number of species found in only one habitat.

Figure 6: Number of priority vascular plant species under each threat category in each habitat.
Figure 7: Number of important vertebrate species under each threat category in each habitat.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Figure 8: Number of priority species found in one habitat alone, for each habitat.
It is evident from figs. 6, 7 and 8 that cliffs constitute the most important habitat in Gibraltar for species
with an unfavourable international conservation status. This is true for both vascular plants and vertebrates.
This is not surprising. Gibraltar holds an extensive network of cliffs and steep, rocky slopes, making
the Rock ideal for species that favour cliff habitats. Many of the internationally threatened or vulnerable
vertebrates found in Gibraltar rely on cliffs as breeding sites. The Peregrine Falco peregrinus, the Eagle
Owl Bubo bubo and the European Free-tailed Bat Tadarida teniotis are examples. The importance of cliffs
to plant species derives from two main factors in addition to their extent. The Rock is composed of Jurassic
limestone, unlike the Spanish countryside to the north. This means that limestone-loving plant species will
favour Gibraltar but not nearby Spain. The second factor is that Gibraltar lies close to North Africa, and is
composed of a similar limestone to that found in the closest parts of Morocco. This means that some North
African species are found only in Gibraltar, and nowhere else in Europe. These North African species, as
well as the species and other taxa that are restricted to the Rock, are all cliff specialists. These examples
illustrate the importance of conserving cliff habitats in Gibraltar. These habitats are currently under threat
in Gibraltar. Chapter 4 discusses their importance more fully, as well as the factors threatening these and
steps that should be taken to conserve them.
Figures 6 and 7 suggest that, although the Upper Rock harbours more priority species than other sites,
it is actually the habitats that cover a proportionally small area that are most important for these species.
The maquis, which covers the majority of the Upper Rock’s surface area, is actually fairly poor in priority
plant species, and not as rich in priority vertebrate species as some other habitats. The maquis is also fairly
poor in invertebrate species richness and density (pers. obs.).
The importance of cliff habitats, a large proportion of which are found within the Nature Reserve, has
already been discussed. Garigue habitats, which cover only a small proportion of the Upper Rock’s surface
area, and which are decreasing in size and threatened by the encroaching maquis, hold the highest
number of both priority vascular plant and vertebrate species. In addition, this habitat type is extremely rich
in invertebrates and supports important populations of the endemic beetle Buprestis sanguinea calpetana
(pers. obs.). The importance of garigue habitats when compared to the dense maquis, as well as their
threatened status, would suggest that habitat management is necessary both to maintain current areas of
garigue and to clear some areas of maquis to make way for garigue. Although large areas of the maquis
should be conserved, due largely to the unique composition of this habitat on the Rock, some areas should
be cleared partially and enriched with tree species that were found on the Rock before its Mediterranean
woodland was cleared, as recommended by Perez & Bensusan (2005). These actions would enhance the
Nature Reserve’s biodiversity considerably.

Chapter 4 consists of Action Plans for sites and habitats. Action Plans for priority species comprise
chapter 5. Action Plans have only been prepared for species that are of serious conservation concern, and
for which adequate knowledge of the species’ biology, distribution and existing threats is available (table 2).
Table 2: Species for which Action Plans have been prepared.
Birds
Falco naumanni Lesser Kestrel
Falco peregrinus Peregrine Falcon
Alectoris barbara Barbary Partridge
Bubo bubo Eagle Owl
Phalacrocorax aristotelis desmarestii Western Mediterranean Shag
Mammals
All Cetaceans Whales & Dolphins
Macaca sylvanus Barbary Macaque
Vulpes vulpes silacea Red Fox
Oryctolagus cuniculus Rabbit
Pipistrellus pygmaeus Soprano Pipistrelle
Miniopterus schreibersii Schreiber's Bat
Vascular Plants
All Orchids
Cerastium gibraltaricum Gibraltar Chickweed
Silene tomentosa Gibraltar Campion
Thymus wildenowii Gibraltar Thyme
Ononis natrix ramosissima var. ramosissima Gibraltar Restharrow
Limonium emarginatum Gibraltar Sea-lavender
Iberis gibraltarica Gibraltar Candytuft
Saxifraga globulifera var. gibraltarica Gibraltar Saxifrage
Laurus nobilis Bay Tree
Fraxinus angustifolia Narrow-leaved Ash
Insects
Buprestis sanguinea calpetana A buprestid Beetle
Arachnids
Macrothele calpeiana Gibraltar Funnel-web Spider
Terrestrial Molluscs
Acicula norrisi A Snail
Osteophora calpeiana A Snail
The Species Action Plans contain a short description of their biology and global distributions. They
include more detailed accounts of local distribution and particularly emphasise the threats and action
required with a specific summary of the species’ protection status and local population trends.
Key Species & Habitats
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4. Habitats

Biodiversity Action Plan, Gibraltar: Planning for Nature
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4. Habitats
Habitats are a key element in the diversity, density and distribution of biological species. The variability
and physical condition of these habitats constitute an important factor in the conservation of many of our
native species and therefore habitats form an integral part of the Biodiversity Action Plan. The conservation
of habitats will, in most cases, ensure the welfare of the species found within each. However, the particular
requirement of some species and their restricted distribution means that there is a need for specific habitat
management processes to ensure the survival and conservation of those particular species.
Consequently the habitat action plans call for the incorporation of the needs of the key species of wildlife
found within habitats to ensure that there is no loss in biodiversity and that all wildlife is conserved.
With a terrestrial area of 5.8 km 2 and a marine area of territorial waters extending three nautical miles
from the shore, except at a mid-point in the Bay of Gibraltar, Gibraltar’s habitats are inevitably restricted.
Yet even taking account of its size, the biological diversity of the area is large, and includes some endemic
and near-endemic subspecies or varieties. Moreover, the importance as a migratory route for avian, airborne
invertebrate and marine species make Gibraltar and the area of the Strait an important site for the
conservation of ecosystems and habitats.
The habitats that make up the territory of Gibraltar can be found within the two main ecosystems. These
are the terrestrial and the marine ecosystems, which are sub-divided into some of the representative habitat
types found in the Mediterranean region. Some of these areas are delineated by topographical characteristics;
others are formed by natural and/or artificial boundaries as in the case of the Upper Rock Nature
Reserve, whereas some are bordered by the nature of their underlying geology or the sea bed.
Figure 1: Main Terrestrial habitat zones, some incorporating
one or more Mediterranean habitat types.
Habitats
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Terrestrial Habitats
1. UPPER ROCK NATURE RESERVE
The Upper Rock is bordered by the cliffs of the North Face and the summit ridge, and is bounded to the
south and west mainly by cliffs and the ‘unclimbable fence’ which runs approximately along the 200m contour.
The entire Upper Rock was in MoD hands until the 1970’s, when most of the area was handed over
to the Gibraltar Government, with the MoD retaining some smaller areas. The Upper Rock was marketed
as a tourist site by the then Gibraltar Tourist Office.
1.1. Current Status
Overall responsibility for the Upper Rock Nature Reserve comes under the Government of Gibraltar,
with responsibility shared by the Gibraltar Tourist Board and the Ministry for the Environment.
Within the Reserve three small residential areas can be found: Poca Roca, Bruce’s Farm area and
Devil’s Gap Battery area, housing a total of approximately 20 families. There is also a Drug Rehabilitation
centre, a nature research facility run for GONHS by the Gibraltar Trust for Natural History and the GONHS
field centre at Jews Gate. Gibraltar is riddled with caves, of which a total of 30 can be found within the
Reserve, some containing archaeological deposits and others important for bats.
1.2. Habitats
The vegetation on the Upper Rock Nature Reserve has changed considerably in recent centuries
(Cortes 1979, Perez & Bensusan 2005).The succession of this vegetation can be seen in old prints, paintings
and photographs of Gibraltar. In these, one can see how the growth has progressed from the lower
reaches of the Upper Rock where the soil is deeper, to the upper, steeper and more exposed areas, where
soil is limited to crevices and recesses in the limestone.
The vegetation on the Upper Rock has developed in the last 200 years and forms the largest expanse
of natural vegetation in Gibraltar. A vegetation survey was carried out by Cortes (1979), who recorded five
different vegetation-types on the Upper Rock: High Maquis, Low Maquis, Maquio-garigue, Garigue, and
Pseudosteppe and Steppe. As part of the ‘Upper Rock Nature Reserve Management Plan’, an extensive
survey of the vegetation was carried out in 2002 to include future recommendations of habitat management
(Perez & Bensusan, 2005). The resulting 57 sample areas were then classified into vegetation types
according to those used by Cortes (1979). The complete vegetation map for the Upper Rock Nature
Reserve is reproduced here.
Figure 2: Mediterranean habitat types within the Upper Rock Nature Reserve (from Perez & Bensusan 2005).

The current composition of the vegetation of the Nature Reserve is composed of several habitat types
of community interest that fall under Annex I of the Habitats Directive and require the designation of Special
Areas of Conservation (SACs). Amongst these are:
• Mediterranean Sclerophyllous Forests dominated by the Olive Olea europea and Olive scrub, which
reaches 12m in the high maquis. The Carob Tree Ceratonia siliqua is slowly re-establishing itself in
the lower reaches of the Reserve and these two species form the main component of this habitat.
• Vegetated sea-cliffs of the Mediterranean coast especially those with endemic Limonium spp.
These can be found around the Mediterranean Steps with the limestone sea cliffs harbouring perennial
plant communities including Gibraltar Sea-lavender Limonium emarginatum, endemic to the Strait
of Gibraltar.
• Thermo-Mediterranean and Pre-steppe Brush is found on parts of the western slopes of the Rock
and especially Rock Gun. This habitat is extremely important for the breeding Barbary Partridge
Alectoris barbara, as a stop-over site for migratory birds and for foraging Barbary macaques.
• Mediterranean Arborescent Matorral includes matorral with Sweet Laurel Laurus nobilis. This is
representative of Mediterranean matorral covering most of the western slopes of the Nature Reserve,
dominated by Wild Olive Olea europea, Osyris quadripartita, Mediterranean Buckthorn Rhamnus
alaternus, and Lentisc Pistacia lentiscus, with individual Sweet Laurel Laurus nobilis, and Nettle Tree
Celtis australis, scattered within. The laurel-containing matorral is mainly found on the south-western
slopes. The presence of this species makes it a Priority Habitat. This habitat is important as a
stopover site for migratory birds and holds populations of the Gibraltar Funnel-web Spider Macrothele
calpeiana and the Horseshoe Whip-snake Coluber hippocrepis.
• Chasmophytic Vegetation on Rocky Slopes of calcareous sub-types can be found on the northern
and eastern cliffs of the Rock, including the outcrops of the cliffs along the western side. Plants of
particular interest found within this habitat type include Gibraltar Saxifrage Saxifraga globulifera gibraltarica,
Gibraltar Chickweed Cerastium gibraltaricum, Gibraltar Thyme Thymus wildenowii, Wall
Helichrysum Helichrysum rupestre, and Gibraltar Candytuft Iberis gibraltarica. The endemic Gibraltar
Campion Silene tomentosa, which was thought to be extinct (Cortes & Linares, 1993) has also been
found in this habitat.
• Other Rocky Habitats there are caves that are not opened to the public. These are largely unspoilt
caves, some possibly containing roosting or breeding bats, all of which are protected.
1.3 Current Factors affecting Habitat
Most factors affecting the habitats of the Nature Reserve have been addressed in Perez & Bensusan
(2005) and a short summary is given here.
• Lack of habitat management.
• Touristic development pressures and speculative projects such as the Funicular railway.
• Spread of exotic species.
• Excessive traffic and pollution.
• Uncontrolled visitor numbers leading to litter and fire risk and undue disturbance.
• Lack of maintenance of former MoD firebreaks.
• Encroachment of trees and shrubs in Pseudosteppe habitat, leading to a simplification of vegetation.
1.4 Current Action
1.4.1 LEGAL STATUS
The Government designated the area of the Upper Rock as a Nature Reserve in 1993 under the ‘Nature
Conservation Area (Upper Rock) Designation Order, 1993’ (L/N 51 of 1993).
Conservation and protection measures are afforded to all species of birds found within the Reserve
under the Nature Protection Ordinance (L/N 13 1991), and in particular those listed in the EC Birds Directive
under Annex I of Council Directive 79/409/EEC, and can be seen in chapter 2. The conservation of natural
habitats and of wild fauna and flora is covered in the EC Habitats Directive (Council Directive
92/43/EEC). Other species of primary importance, including some that were left out of the Council
Directive, are included in the Nature Protection Ordinance (LN/11 of 1991).
As part of the requirement of the Habitats Directive to nominate Sites of Community Importance (SCIs)
under the Natura 2000 Network, the Government of Gibraltar has now designated the Upper Rock Nature
Reserve as one of the candidate Special Areas of Conservation (cSACs) and has submitted the proposal
to Brussels.
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1.4.2 MANAGEMENT, RESEARCH AND GUIDANCE
The Government of Gibraltar commissioned GONHS to prepare a feasibility study and management
plan for the Upper Rock Nature Reserve in late 2002. Funding was obtained via the European Union under
the European Regional Development Fund Objective 2 programme, and the report, ‘Upper Rock Nature
Reserve. A Management and Action Plan’ (Perez & Bensusan, 2005) was submitted to the Government.
That report analyses the Nature Reserve from environmental, historical, natural and touristic perspectives
and addresses objectively the problems and concerns poised by the different stakeholders. It provides a
management plan using a programmatic approach and presents goals and objectives together with a list of
recommendations after each chapter including a costed action plan.
Perez & Bensusan (2005) proposed a number of tasks for environmental management and maintenance,
employing a recommended 10/12 men work team, of which the following are directly relevant to biodiversity
conservation:
• Annual clearing of roadside vegetation.
• Clearing of vegetation along paths.
• Removal of invasive species of plants.
• Control of Acanthus mollis.
• Removal of woody vegetation around the Rock Gun area.
• Removal of woody shrubs in Garigue habitat.
• Planting programme in woodland sites using Mediterranean species.
• Habitat management around tourist sites.
• Dead pine trees to be replaced.
• Clearing of all refuse within caves.
• Clearing of firebreaks.
• Habitat/site restoration within habitat types of Community interest that fall under the Habitats Directive.
It is encouraging to see that Martin’s Path, between Jews’ Gate and St. Michael’s cave, was cleared of
encroaching vegetation in the autumn of 2004 and opened up to the public, although much work remained.
In December of 2005 a works team was finally allocated to the Nature Reserve by the Ministry for the
Environment and under guidance from GONHS, completed the clearing of Martin’s Path, including the
removal of the obstructing dead trees. They are currently working on clearing other pathways. This team
could be deployed to carry out other habitat management tasks.
1.5 Conservation Direction
The Upper Rock Nature Reserve is an important area for biodiversity, containing most of the habitat
types found in Gibraltar and a large percentage of the species that have independent species action plans.
The implementation of the goals and objectives presented in Perez & Bensusan (2005) would cover all the
necessary requirements of the Nature Reserve at present. The works team recommended in the
Management and Action Plan would be the fundamental core unit that would tackle the habitat management
and other relevant works within the Nature Reserve. The first stage would involve major clearing and
reparation. Once the initial phase has been addressed then works would concentrate on annual maintenance
and remedial works.
A wardening system would be crucial to the Management Plan of the Upper Rock. The wardens would
monitor the Nature Reserve and guarantee its viability, partly through supervising and controlling the various
programmes carried out by the works team.

2. CLIFFS
Figure 3: The east side cliffs above Catalan Bay (L. Linares).
The Rock of Gibraltar largely consists of limestone cliffs. The boundary of the Nature Reserve is bordered
by the majestic North Face cliff to the north, which rises from sea-level to a height of 412m, and the east side
cliffs that rise above the talus and sand slopes to the east. To the west a line of cliffs of approximately 70m in
height rise up from the Lower Slopes and the Nature Reserve buffer zone from just south of Bruce’s Farm all
the way to Rooke Battery, where they become steep slopes. Cliffs also surround the raised beach of Windmill
Hill and sea cliffs extend all the way from Sandy Bay to the South Mole. The heavily fractured zone of North
Gorge is also bordered by the cliffs of Windmill Hill to one side and the Buena Vista cliffs to the other. The fault
system also runs north and falls sharply to the west as a stretch of vertical limestone cliffs running below the
Buena Vista, levelling off and again falling towards Rosia.
The cliffs on the Rock of Gibraltar can be divided into two categories. Sea-cliffs run from Sandy Bay to the
South Mole. The others are inland cliffs, surrounding the Nature Reserve and including those found around the
North Gorge and the Buena Vista area.
A number of caves can be found in many of the cliffs of Gibraltar. Some are located at the base of the cliffs
and have been weathered by the action of the sea. Others are found along existing fissures and fault lines with
their entrances high up on the vertical faces. The constant temperature and relative humidity of some of these
caves means that they provide a habitat for a number of species. Two species of bats, Schreiber’s Bat
Miniopterus schreibersii and Mouse-eared Bat Myotis myotis, were once common in many of these caves and
may still use them as roosting, and breeding sites. The Free-tailed bat Tadarida teniotis frequents cracks and
fissures along the cliff face. Several plant species can be found growing in the humid walls of cave entrances.
A fly species (Diptera), yet to be identified, aestivates on the cave walls in huge numbers during the hot late
summer and early autumn period.
There is relatively little distance from the shoreline anywhere on the Rock and therefore all the cliffs found
in Gibraltar bear the influence of the sea, be it from the strong south-westerly winds or the humid and salt-laden
levanter which often causes a cloud rising over the Rock. However, it is the sea-cliffs that bear the brunt of
adverse weather conditions. A number of plant species, resistant to these conditions grow on these cliffs. One
of these, the Gibraltar Sea lavender Limonium emarginatum, is restricted to the Strait area.
The inland cliffs are a vitally important habitat for many of Gibraltar’s special plants, most of which are cliffloving
species. North-facing and shaded areas in particular provide a refuge for many of Gibraltar’s endemic
and near endemic species. Among the species to be found here is the endemic Gibraltar Campion Silene
tomentosa. Other important and scarce species also grow in the clefts and fissures of the cliffs and rocky outcrops
of the Nature Reserve. These are the Gibraltar Saxifrage Saxifraga globulifera, Gibraltar Thyme Thymus
wildenowii, Gibraltar Candytuft Iberis gibraltarica and Gibraltar Chickweed Cerastium gibraltaricum.
Several bird species are characteristic of cliff habitats and some use the cliffs as nesting sites. The North
Face of the Rock holds the last remaining Lesser Kestrels Falco naumanni in Gibraltar. This species is afforded
the category of a bird of ‘global conservation concern’ by Birdlife International (Tucker & Heath 1994, Heath
& Evans 2000) and is listed under Annex 1 of the EC Birds Directive 79/409/EEC. Irby (1895) recorded vast
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numbers breeding there, but by 1980 only 15 pairs were recorded (Cortes et al.1980). More recently, numbers
have been down to four pairs in some years, although more pairs breed in most years.
Other important birds of cliff habitats are the Peregrine Falco peregrinus, with the very high density of 7
breeding pairs in Gibraltar, the Little Owl Athene noctua, a pair of Ravens Corvus corax, Eagle Owl Bubo bubo,
Alpine Swift Apus melba with breeding pairs on the North Face and the Governor’s Beach cliffs, Mediterranean
Shag Phalacrocorax aristotelis desmarestii and Blue Rock Thrush Monticola solitarius. The Lesser Kestrel,
Peregrine, Eagle Owl and the Mediterranean Shag are listed under Annex 1 of the EC Birds Directive and
included in the Species Action Plans.
2.1 CURRENT STATUS
At present only some of the cliffs that form the boundary of the Upper Rock Nature Reserve are within the
limits of the Reserve. Most of the west, north and east cliffs fall outside the designated zone although the
boundary in these areas is not clearly defined. Perez & Bensusan (2005) recommend that the cliffs surrounding
the Nature Reserve be included within the boundary as all cliff habitat falls under one of two EC Habitats
Directive priority categories that require the designation of Special Areas of Conservation. In addition they recommend
that all cliff habitats in Gibraltar be protected as part of a Natura 2000 site under the EC Habitats
Directive (92/43/EEC).
The two relevant habitat types are ‘Vegetated sea cliffs of the Mediterranean coasts (with endemic
Limonium spp)’, and ‘Chasmophytic Vegetation on Rocky Slopes’. These two habitat types were assessed by
Cortes (1994), and this assessment is reproduced below.
Vegetated sea cliffs of the Mediterranean coasts (with endemic Limonium spp)
Location:
Sea cliffs from Sandy Bay to Europa Point and Rosia Bay. This includes the sea cliffs, which rise up to Martin’s
Cave around Mediterranean Step’s where Gibraltar Sea Lavender Limonium emarginatum can also be found
growing.
a) Degree of representativity of the natural habitat type on the site.
Representative of Mediterranean limestone sea cliff with perennial plant community including Aeonium haworthii
and Aeonium arboreum, and Limonium emarginatum, endemic to the Strait of Gibraltar.
b) Area of site covered by habitat in relation to the habitat in Gibraltar.
50%.
c) Degree of conservation.
Poor to very good. Areas have accumulated rubbish and rubble, and others have been polluted by effluent from
the refuse incinerator and the refuse holding area. The area within the Nature Reserve is unspoiled due to its
inaccessibility and remoteness.
d) Global assessment.
The occurrence of an endemic makes this an area of global importance. It is also unique in landscape value
together with the rest of the Mediterranean Steps.
Chasmophytic Vegetation on Rocky Slopes (Calcareous sub-types)
Location:
Northern and eastern cliffs of the Rock of Gibraltar, and the outcrops of the cliffs on the western side of the Rock.
a) Degree of representation of the natural habitat type on the site.
Extensive areas of mostly unspoilt chasmophytic vegetation representative of the habitat. Plant species of particular
interest include Gibraltar Saxifrage Saxifraga globulifera gibraltarica, Gibraltar Chickweed Cerastium
gibraltaricum, Gibraltar Thyme Thymus wildenowii, Wall Helichrysum Helichrysum rupestre, and Gibraltar
Candytuft Iberis gibraltarica. The endemic species Gibraltar Campion Silene tomentosa, until recently presumed
extinct (Cortés & Linares 1993) has been rediscovered in this habitat where the known world population is of two
plants.
b) Area of site covered by habitat in relation to the habitat in Gibraltar.
50%
c) Degree of conservation.
Very good. Some sites more accessible and close to human habitation require monitoring.
d) Global assessment.
The chasmophytic vegetation of the Rock of Gibraltar is representative of areas of limestone in the
Mediterranean, but has added global importance in the occurrence within it of taxa which are either endemic or
with affinities to North Africa.

The unique flora found on cliff habitat is protected under the Nature Protection Ordinance 1991 (L/N 11
of 1991). Gibraltar’s more special plant species are listed under Schedule 3 of the ordinance. They are
the following:-
Table 2. Important Gibraltar flora listed under Schedule 3
of the Nature Protection Ordinance 1991.
Common Name Scientific Name
Gibraltar Chickweed Cerastium gibraltaricum
Gibraltar Campion Silene tomentosa
Gibraltar Candytuft Iberis gibraltarica
Gibraltar Saxifrage Saxifraga globulifera
Gibraltar Restharrow Ononis natrix
Gibraltar Sea Lavender Limonium emarginatum
Gibraltar Thyme Thymus wildenowii
Parsley Petroselinum crispum
Giant Tangier Fennel Ferula tingitana
Succowia Succowia balearica
Of these, only the Gibraltar Restharrow Ononis natrix and the Giant Tangier Fennel Ferula tingitana are
not cliff specialists.
The endemic Gibraltar Campion and near endemic species of plants were not included in the Habitats
Directive because the member state, the United Kingdom, did not consult the Gibraltar authorities.
Nonetheless Gibraltar submitted these special plants under ‘Other important species of fauna and flora’ to
be incorporated within the Habitats Directive with a request for their inclusion within those species requiring
special protection measures under Annex II.
Details of the populations of Peregrines, Lesser Kestrels, Eagle Owls and Shags are given in their
respective action plans. A pair of Ravens established themselves on the Rock in 2001 after a period of 30
years. Breeding has been attempted unsuccessfully on an annual basis, but one of the birds is missing a
foot and this may explain their lack of success.
The large numbers of Alpine Swifts Apus melba, as seen in the days of John White in the 18 th century,
no longer occur. Nevertheless some pairs of this large swift still breed, although in very small numbers.
Numbers are apparently stable, although due to the small breeding population, the species could become
extinct from Gibraltar at any time. A cliff dwelling species in Gibraltar, it can be found nesting in the recesses
of the roof of the entrance to Gorham’s cave at Governor’s Beach and in a few crevices on the North
Face of the Rock.
The Little Owl Athene noctua breeds in small numbers along the cliffs below Windmill Hill, the east side
cliffs and the North Face of the Rock, with at least one pair in the Camp Bay/Little Bay area and another
below the Apes’ Den. The removal of the water catchments and subsequent re-establishment of the sand
slope habitat should prove an opportunity for an increase in the number of pairs on the east side of the
Rock.
The Blue Rock Thrush Monticola solitarius can be found in much the same areas. This bird will breed
on sea cliffs as well as the cliffs inland, and also close to urban areas. The species is resident, although
some migrants are observed in late October and again in March.
Other bird species frequenting cliffs include the Yellow-legged Gull Larus michahellis, Wren Troglodytes
troglodytes, Crag Martin Ptyonoprogne rupestris in the winter, and occasionally Rock Bunting Emberiza cia.
Many caves were once roosting and breeding sites for large colonies of Schreiber’s Bat Miniopterus
schreibersii and Mouse-eared Bat Myotis myotis in the middle of the last century (pers. obs. & Palao
Unpubl.), and are still potential sites for these mammals. In recent years the former species has only been
recorded in one tunnel. The European Free-tailed Bat Tadarida teniotis is a cliff dwelling species, using
small clefts and fissures in the rock face as roosting and breeding sites. It is certainly present in good numbers
all over Gibraltar, as evidenced from its audible calls.
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All bats are afforded protection under Schedule 3 of the Nature Protection Ordinance 1991 (L/N 11 of
1991). Schreiber’s, Mouse-eared, Pipistrelle and European Free-tailed Bats are also covered in Annex I of
the EUROBATS agreement. Schreiber’s and Mouse-eared Bats are listed in Annex II of the Habitats
Directive, and the European Free-tailed bat is included in other important species of flora and fauna within
the same Directive.
2.2 CURRENT FACTORS AFFECTING HABITAT
As the human population of Gibraltar continues to increase, the Government of Gibraltar is under pressure
to provide accommodation. The land reclamation policy of the late 1980’s and 1990’s has already
used up most of the potential shallow water areas within and outside the Gibraltar Harbour, creating large
residential and commercial zones, although several development and reclamation projects are still in the
pipeline. On the east side of the Rock, a further reclamation project will provide for additional development.
This may substantially increase the human population leading to mounting pressure to provide additional
services infrastructure, and further development. Already there are few marine areas left that would be economically
viable for reclamation and those that are available are increasingly deep. Therefore developers
have been looking on land for potential open spaces.
Two projects, Maida Vale and North Gorge, have received planning permission from the Development
and Planning Commission, even though much of the development is situated just a few metres from a cliff
and in a geologically unstable fractured and fault zone. The justification for the location seems unreasonable
but due to the high prices the properties fetch and the enormous profit margin for developers the environment
pays the ultimate price. The works include cliff stabilisation, involving removal of vegetation,
scraping, grouting of crevices and fissures with concrete and anchoring of boulders, followed in places by
the installation of wire mesh. This practice is meant to reduce personal liability rather being a health and
safety exercise, for eventually the cliff stabilisation works will rust and wear away and the properties will be
left at risk. The logical strategy should be: ‘if a site is dangerous then do not build on it’.
Following a large collapse of a disused tunnel in the Camp Bay area, the Government contracted the
services of Sharrock Shand Ltd who sub-contracted the works to Golder & Associates Ltd based on the
geo-technical advice by Mott MacDonald, to carry out an assessment of the Camp Bay and Little Bay cliffs.
In their opinion, the areas in question required extensive cliff stabilisation. This resulted in large areas of
the cliff at Little Bay, holding important native plants, being grouted and concreted over. It also affected several
other species of flora and included an area where Blue Rock Thrushes and Little Owls nested. The
resulting eyesore was clearly inspired by an overenthusiastic application of stabilisation methods. Much of
the natural appearance of the cliff area in this location has been lost together with several plant populations
above Little Bay (Perez & Bensusan, 2005).
Mitigating factors included a survey carried out by the GONHS climbing section to assess the flora and
fauna of a large part of the cliffs that were to be concreted over. This report recommended areas where
mesh should be favoured over concrete in order to safeguard plant species, areas where scraping could
be damaging to the plant communities, and in the areas where potential nesting sites for birds had been
lost, the erection of nest boxes for Little Owl, Kestrel, Pallid Swift and Blue Rock Thrush.
Following this, cliff stabilisation works have been carried out on the Windmill Hill south cliffs where again
a residential area has been built in close proximity to the cliffs, and the cliffs above the old Governor’s
Cottage where a crematorium is to be built. Further residential development in the North Gorge has also
required extensive cliff stabilisation with rock bolting, scraping and grouting and the erection of wire mesh.
Another development at the Naval Hospital area has also required, according to the advice of the contractors,
cliff stabilisation even though there has always been a roadway below a cliff that carries close to three
quarters of a million tourists a year to the Upper Rock Nature Reserve. A new residential development at
Maida Vale will apparently involve the stabilisation of the cliffs below Rooke Battery. These cliffs form the
boundary of the Nature Reserve and hold an interesting plant community, as well as nesting birds. There
is a concern that the same entity assessing cliffs later carries out the proposed works, leading to questions
of propriety. An independent assessment of these recommendations should be made on each occasion.
In addition, it is important that initial assessments include direct involvement from GONHS, so that proposals
prepared already take account of ecological requirements.
The Rock of Gibraltar is surrounded by cliffs, and the authorities should ensure that any developments,
be they residential or commercial, are not in close proximity to the cliff base and an appropriate buffer zone
should ensure the safety of these developments. This has happened in several areas, including Catalan
Bay. Nevertheless there are extensive areas of Gibraltar, especially on the east side of the Rock, where

oadways and residential or commercial properties are already sited close to the cliffs, and where the possibility
of rock falls, due to the steep nature of the slopes underlying the cliffs, is always great. Historically,
Catalan Bay has been affected by severe rock falls, as has Both Worlds at Sandy Bay. Here the erection
of safety nets on the sand slopes by MoD before the handover of this site to the Gibraltar Government has
ensured a degree of protection. Rock falls have also taken place elsewhere such as Devil’s Tower road
at the crossroads with Eastern beach and at the entrance to the tunnel past the oil tanks at Sandy bay,
where unfortunately there was a fatality. In this case the Gibraltar Government decided to close off the
roadway, but rock falls are likely to occur anywhere along this and other roads and developed areas, where
these are near cliffs. Perez & Bensusan (2005) argue that cliff stabilisation is certainly not the answer.
Already some areas that were stabilised in the Camp Bay and Little Bay areas are showing signs of fracturing
and erosion and the concrete covering is giving way and allowing rock falls, as well as falling itself.
We have to realise that there is an element of risk if buildings and roads are situated close to cliffs. A buffer
zone to act as a catchment area for falling rocks is the best answer. This will solve the environmental problem
of cliff habitat degradation and allow for safe residential developments without the added very high cost
of cliff stabilisation.
2.3 CURRENT ACTION
A specific management plan for cliffs is needed to establish the criteria and requirements for cliff stabilisation
in relation to risk management and urban development.
3. LOWER SLOPES AND BUFFER ZONE
Figure 4: Part of the Lower Slopes site with maquio-garigue habitat (L. Linares)
The Lower Slopes of the Upper Rock are situated to the west of the Nature Reserve at an average elevation
of 130m, and form the Buffer Zone between the urban areas of the upper town and the Upper Rock
Nature Reserve. The Lower Slopes are bordered to the east mainly by cliffs along the Nature Reserve’s
boundary and slope steeply in places over 100m down to the upper town boundary. The geological composition
of these slopes differs from much of the rest of Gibraltar in that the underlying rock is composed
of shale and mudstones with a few occasional outcrops of limestone (Rose & Rosenbaum1991). This area
runs south of the Waterworks in the Calpe area to the area below Devil’s Gap, but, for the purposes of this
study, the buffer zone also extends from here to Maida Vale above Europa Road. Further outcrops of this
rock and soil type runs above Mount Road south below Jews’ Gate ending in an area around Lathbury
Barracks. Water penetration in this rock type is minimal and prominent features of the main area of the
Lower Slopes are two eroded gullies running east to west, one of which is known as Arengo’s Palace Gully.
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3.1 Current Status
3.1.1 LEGAL STATUS
The Lower Slopes and Buffer Zone lie outside the Upper Rock Nature Reserve and therefore do not fall
under the protection of the ‘Nature Conservation Area (Upper Rock) Designation Order 1991’ (L/N 51 of
1993) and the ‘Nature Conservation Area (Upper Rock Nature Reserve) (Protection and Regulation)
Regulations’ (L/N 52 of 1993). Nevertheless the flora and fauna found within this habitat zone enjoy the
protection of the ‘Nature Protection Ordinance 1991’ (L/N 11 1991).
3.1.2 MANAGEMENT, RESEARCH & GUIDANCE
When the Upper Rock was a military area and out of bounds in the early and mid 1900’s, the Lower
Slopes, between Calpe and Devil’s Gap and below Jews’ Gate, were cleared of all tall vegetation as a firebreak
and for security purposes annually, and goats were grazed there. These processes kept the vegetation
open, as can be seen in the photograph of the period (See Fig.5). Shortly after the transfer of the
Upper Rock to the Gibraltar Government in the early 1970’s, the Lower Slopes were no longer maintained
and the regeneration and succession of the vegetation slowly took place. This vegetation has slowly grown
in size and height with the dominant shrubs of Spiny Broom Calicotome villosa and Olive Olea europea
interspersed with low growing plants and the occasional Nettle Tree Celtis australis. The buffer zone
behind the Rock Hotel is composed of high maquis – the same habitat type as most of the Upper Rock –
as this area did not receive the habitat management imposed by the MoD.
Figure 5: Gibraltar in the early 1900s. Note the absence of vegetation on the Lower Slopes.
(R. Wheeler)
Access is difficult since there is no roadway that passes close to or intersects the Lower Slopes. This
isolation has proved a blessing for wildlife. The Buffer Zone area between the Rock Hotel and the cliff is
the property of the Hotel owners and has remained undisturbed far longer than the Lower Slopes. The vegetation
here was allowed to grow, with olive trees reaching up to six metres. A road runs down from Devil’s
Gap and joins Europa Road beside the Casino now south of the Hotel. This roadway is derelict, and only
used by the Fire Brigade for emergency purposes.
Several plant species, particularly orchids, are found here and nowhere else, possibly due to composition
of the soil and underlying rock (Linares 1988, 1990, 1994). Approximately half of Gibraltar’s plant
species can be found growing on the Lower Slopes area, of which 27 are protected under part II, Section
11 of the Nature Protection Ordinance 1991 (L/N 11 of 1991), in that they are not specified under Schedule
2 of the Ordinance. Tables 3 and 4 list some of the rare plants of the Lower Slopes.
Table 3: Special plants found exclusively on the Lower Slopes.
Common Name Scientific name
Shepherd's Needle Scandex pecten-veneris
Yellow Bartsia Parentucellia viscosa
Cut-leaved Lavender Lavandula multifida
Pale Flax Linum bienne
Narrow-leaved Red Vetchling Lathyrus setifolius
Bean Trefoil Anagyris foetida
Clubmoss Selaginella denticullata
Gibraltar Saxifrage Cerastium gibraltaricum
From Perez & Bensusan 2005

Table 4: Orchids found on the Lower Slopes.
Common Name Scientific name
Yellow-bee Orchid Ophrys lutea subsp. lutea
Brown-bee Orchid Ophrys fusca subsp. fusca
Mirror Orchid Ophrys speculum subsp. speculum
Bumble-bee Orchid Ophrys bombiliflora
Small-flowered Serapias Serapias parviflora
Autumn Lady's Tresses Orchid Spiranthes spiralis
Two-leaved Gennaria Gennaria diphylla
From Perez & Bensusan 2005
The Lower Slopes are also used extensively by breeding Barbary Partridges Alectoris barbara,
Blackcaps Sylvia atricapilla and Sardinian Warblers Sylvia melanocephala, and the surrounding cliffs hold
several pairs of Blue Rock Thrushes Monticola solitarius. This area is also used as a feeding are by bats
including Schreiber’s Bat Miniopterus schreibersii, which require open ground.
3.2 Current Factors affecting Habitat
Several negative factors affecting the habitat of the Lower Slopes must be remedied if the area is to
remain an important site for orchids and other rare plants. All these factors are interlinked and should be
tackled together for there to be any chance of success in conserving the habitat.
• Lack of habitat management.
• Increase in density of vegetation.
• Risk of fire.
• Excessive grazing and erosion caused by feral goats in some areas.
• Dumping of rubbish.
3.3 Current Action
None.
3.4 Threats
The area is under threat from construction developments, with several projects having been proposed.
Of these the most significant was the proposal for a road connecting the Calpe area to the Green Lane
roadway. This was allegedly to alleviate traffic in the upper town and avoid congestion with tourist traffic
descending from the Nature Reserve. This project, which was to be carried out by ‘Kumigai Gumi’, a
Japanese firm, would have included the development of the land on either side of the road, thereby completely
destroying the whole of the Lower Slopes area. Thankfully the project was shelved in the 1980s,
although there has been occasional interest in resurrecting it since then. The use of the Great North Road,
a tunnel running from the Calpe area near the Moorish Castle and exiting at Maida Vale on Engineer Road,
would achieve the same traffic diversion without the development and destruction of the lower slopes, but
also without the related lucrative benefits for real estate developers.
Another proposed project involves the development of the Lower Slopes above the Rock Hotel and
above Maida Vale for the construction of houses. These speculative construction enterprises would have
the following serious consequences on the Upper Rock Nature Reserve.
• Proximity to the ‘Apes Den’ would bring undesired interaction with humans.
• The development of the Lower Slopes would bring the wildlife of the Nature Reserve into closer contact
with the human population.
• Risk of rock falls would then require unsightly and ecologically damaging cliff stabilisation, grouting,
netting and cementing over.
• Construction of the area will turn the Gibraltar Botanic Gardens into a green island, with little chance
of crossover of wildlife to and from the Nature Reserve.
• Increased risk of fire.
• Increased atmospheric pollution from traffic.
• Increased light and noise pollution.
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3.5 Conservation Direction
Necessary measures include:
• A campaign to highlight the importance of the Lower Slopes and Buffer Zone, not only for the special
plant species, but also as a boundary and green corridor separating the urban town zone from the
Nature Reserve.
• A habitat management programme to reduce the density of encroaching maquis vegetation with the
purpose of creating the open areas that existed in the past. This will also reduce the fire risk to the
Upper Rock Nature Reserve.
• Removal of invasive plant species.
• Removal of remaining poultry and feral pigeon enclosures.
4. TALUS
Figure 6: The Northern Talus slope (L. Linares)
A talus is ‘a sloping mass of rock debris at the base of a cliff’. The talus slope is on the east side of the
Rock at the base of the vertical cliff that towers up to Rock Gun. It extends from the eastern end of Devil’s
Tower Road to Catalan Bay, where the talus slope was quarried for limestone rocks. The formation of the
slope is due to the constant deposition of rocky material from the cliffs above. The main deposition took
place during the glaciations, with the action of rain water freezing and expanding within fissures and
crevices in the rock, fracturing the rocks and breaking them off to fall to the base of the cliff, forming a conglomerate
which fused to form breccias. Wind-blown sands off the Mediterranean Basin, then covered the
talus with a thick mantle, with more rocks later falling from above, to produce the combination of rock and
sand where a unique habitat of plants and animals now exists.
Another talus exists at the base of the cliff that rises up to the Rock’s summit at Spyglass. It is situated
south of Sandy Bay and is contained to the south by a set of north facing cliffs. This slope was quarried
at the same as the other talus slope, and a lot more aggregate was removed, providing an extensive
area where the Admiralty Oil Tanks were situated. Above this the remnant of this talus slope is small and
inaccessible, but contains a less sandy base and more soil cover that has allowed shrubby plants to grow.
In the area between the two talus slopes lie the Great Sand Slopes (5).
4.1 Current Status
4.1.1 LEGAL STATUS
The talus slopes are not currently covered by any environmental legislation or European Directives, but
the general provisions of the Nature Protection Ordinance apply.
4.1.2 MANAGEMENT, RESEARCH AND GUIDANCE
This account applies to the northern talus slope below Rock Gun, since the southern talus slope has
remained inaccessible, except to the GONHS caves and cliffs section, which has covered the area in
search of caves. The slope has not been the object of biological research except in visual surveys.
The talus slopes appears to buttress the majestic vertical sea-cliffs that extend from sea level to over

400m high. Their location on the eastern side of Gibraltar means that they face the morning sun and the
humid easterly winds that prevail during much of the year. The slope is relatively steep, at an angle of over
50°, at which angle the sand remains stable. The composition of this slope can be seen from the quarried
section that has exposed the talus layer. It mainly consists of rock conglomerate with a thin overlying layer
of sands. Sandy soil is restricted in Gibraltar to the isthmus, an original wind-blown dune beach-sand system,
and the ancient windswept sands of the eastern slopes of Gibraltar. (There is also a bed of very fine
red sands found under the southern town area, where it can be seen at the Alameda Botanic Gardens, but
this sand is very different to that on the eastern side.)
The Talus slope has deteriorated in the recent past due mainly to the construction of access roads to
Catalan Bay, rendering the base unstable, so that sand and soil slippage has occurred regularly until the
slope has again achieved a stable angle. The most noteworthy of these landslides covered the roadway,
and access to Catalan Bay was diverted through William’s Way tunnel until the existing road was rebuilt.
Evidence of the original depth of sand and soil of the slope can be seen at the base of the cliff, where weak
sandstone remnants, reminiscent of the fossil dunes of the sand slopes, can be seen in places up to 8m
above the base of the cliff. This demonstrates how susceptible this talus slope is to any degradation at the
base of its slope.
The Talus is an open, unfenced area and access is not restricted to members of the public. Excessive
walking on the Talus, and for that matter the Sand Slopes, is extremely destructive since the nature and
consistency of the soil and sandy layers is weak and any pressure applied underfoot loosens the soil,
exposing the plants’ roots. It is therefore advisable to restrict any access to these slopes unless absolutely
essential.
A key influence on the uniqueness, and hence importance, of the flora and fauna of the Talus slopes
and the Great Sand Slopes has obviously been the nature of underlying soil. Man has not influenced the
vegetation of the area in recent years; although in the past goat herds from Catalan Bay were allowed to
roam freely on these slopes. The lack of records prevents detailed comparison of the present plant community
with the original one. At present the habitat of the talus is a sandy garigue, composed mainly of
grasses and low growing shrubs. Of these, one of the most conspicuous plants, forming small clumps is
the Large Yellow Restharrow Ononis natrix, of which the subspecies ramosissima, variety ramosissima
known as the Gibraltar Restharrow, grows in abundance here. This variety is exclusive to the Rock of
Gibraltar and is therefore the flagship taxon of this habitat. Table 4 lists some of the special plants that can
be found in this habitat.
Table 5: Key plant species found on the Talus slope.
Common Name Scientific Name
Gibraltar Restharrow Ononis natrix var. ramosissima
Montpellier Broom Teline monspessulana
Parsley Petroselinum crispum
Giant or Large -flowered Mullein Verbascum giganteum
Silver Sea Stock Malcolmia littorea
Erect Dorycnium Dorycnium rectum
Gibraltar Candytuft Iberis gibraltarica
Amongst the larger plants and shrubs found on the Talus are some Olive bushes Olea europea, Osyris
Osyris quadripartita, Lentisc Pistacia lentiscus, Tamarisk Tamarix gallica, Joint-Pine Ephedra fragilis and
the Shrub Tobacco Nicotiana glauca, this last a naturalised alien. Other alien species have become established
on the talus, through the action of man: both the Tree Aloe Aloe arborescens and the Hottentot fig
Carpobrotus edulis x acinaciformis, plants that do not set seed, have been planted at the base of the slope
and form large stands that border the roadway. The Hottentot Fig is an invasive species that was originally
used in stabilising sandy habitats and slopes. Although useful in preventing wind-blown erosion, it fails
to anchor the sand and soil sufficiently well due to its weak root structure and the blanket nature of its
growth, excluding all other plants, and is particularly damaging to the native flora and fauna.
The fauna of this habitat is also very varied and has several unique species that are found exclusively
or have their stronghold here.
Several species regularly use the Talus habitat as their feeding or breeding grounds. Amongst the most
prolific is the Yellow-legged Gull Larus michahellis. This slope holds some sixty pairs that breed on the
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ground, many rearing between two and three young. The recently-established Eagle Owls have been using
this habitat to prey on the gulls. Further evidence of this was discovered during a visit to the Talus at the
end of July 2005, when remnants of adults and gull chicks consisting of wings, heads and feathers could
be seen everywhere along the slope. This natural control of the gull population should be encouraged.
Strict protection of the Eagle Owl, covered under the Nature Protection Ordinance and the Birds Directive,
and its foraging habitat must be assured.
The Kestrel Falco tinnunculus has several pairs breeding on the eastern side of the Rock. The birds
are regularly seen foraging on the Talus and Great Sand Slopes, feeding on varied prey items from large
insects to lizards and small birds. The Barbary Partridge, Alectoris barbara, Gibraltar’s flagship bird
species, can also be found commonly on the talus slope. A small population of this bird has become established
here. Their preference for open ground habitats, which is quickly disappearing on the Upper Rock
Nature Reserve due to the succession of the vegetation and the lack of maintenance of open ground areas
and firebreaks, has encouraged some pairs to establish themselves on the Talus slope. This species is listed
under Annex 1 of the Birds Directive and Schedule 3 of the Nature Protection Ordinance.
Table 6: Key bird species using the Talus habitat.
Common Name Scientific name
Kestrel Falco tinnunculus
Yellow-legged Gull Larus michahellis
Barbary Partridge Alectoris barbara
Little Owl Athene noctua
Eagle Owl Bubo bubo
Blue Rock Thrush Monticola solitarius
Black Redstart Phoenicurus ochruros
Rock Bunting Emberiza cia
The habitat of the Talus slope is also ideal for various reptile species. Both the Horseshoe Whip Snake
Coluber hippocrepis and the False Smooth Snake Macroprotodon cucullatus have been seen there. The
Iberian Wall Lizard Podarcis hispanica is mainly found on the rocky parts of the Talus and the cliff base and
the Algerian Sand Racer Psammodromus algirus, occurs mainly on or near shrubs. The Moorish Gecko
Tarentola mauritanica prefers rocky habitat and is therefore at home at the base of the cliff, in crevices and
fissures. However, the key species of this habitat are the skinks. These are lizards with greatly reduced
or vestigial legs that move by serpentine, ‘S’ shaped movements on the sand. Two species are found in
Gibraltar: the Three-toed Skink Chalcides striatus and Bedriaga’s Skink Chalcides bedriagai. Once frequently
found on the isthmus, this sandy habitat has now been reduced to the North Front Cemetery and
the Aerial Farm, and both species were last seen at the former site in the 1980s after which over-zealous
clearing of vegetation has probably resulted in the disappearance of both species. The Aerial Farm may
still hold an isolated population but the stronghold of both species is now the Talus Slopes and the Great
Sand Slopes.
The Talus slopes hold a rich community of sand-loving invertebrates, including Lepidoptera (butterflies
& moths), Coleoptera (beetles), Orthoptera (crickets and grasshoppers) and Neuroptera (antlions and
lacewings). At least five species of ant-lion have been seen regularly in this habitat. Nemoptera bipennis,
recognised by its yellow lace-like forewings and ribbon-like hind wings is common in late May and June.
Grasshoppers can be seen in abundance in late spring with several species awaiting identification.
Grasshoppers feed mainly on grasses and are therefore important in this habitat. Coleoptera include the
darkling beetles (family Tenebrionidae), which are well represented. Many of these beetles also frequented
the isthmus but in the same way as the Skinks, they are now mainly concentrated on the east side
slopes. One beetle species, Buprestis (Yamina) sanguinea (family Buprestidae) can be found on the Joint
Pine Ephedra fragilis, a shrub that grows well on the Talus slope. This species is rare globally, found only
in small areas of north and central Spain and North Africa, with an isolated population at Gibraltar that forms
the endemic subspecies calpetana. It is therefore a key species of this habitat, as is Nemoptera bipennis.
Among the lepidopteran fauna of this habitat are grass-loving moth species, including several species of
the family Noctuidae and Cymbalophora pudica of the Tiger Moth family, Arctiidae.
4.2 Current Factors affecting Habitat
There is very little affecting the current situation of the Talus slopes, but this could change in the near
future due to the proposed Eastside Development nearby. However, the occasional use of the site for
motor cycle scrambling cases great disturbance, destruction of vegetation, and erosion.

4.3 Current Action
None required at present.
4.4 Threats
The proposed Eastside Development project and land reclamation constitute the greatest threat to the
integrity of the northern Talus slope. This proposal involves extensive development on land that will be
reclaimed from the sea, but will also include development of the area adjacent to the base of the talus slope.
The potential risk of rockfalls in this area will then require safety measures to be implemented. If this is
done wisely the environmental impact on the slopes will be greatly reduced. The location of residential
development too close to the cliffs and base of the slope is unacceptable, as this would place residents in
grave danger and require the implementation of an unreasonable amount of safety measures that would
gravely mar the natural appearance of the slope and cliffs and would still not guarantee total protection. If
located at a reasonable distance, this would allow for a rock catchment area that would contain falling
rocks, with appropriate netting and walls in place. We have to bear in mind that at present the area has no
protection whatsoever from rock falls, and this roadway bears a large amount of traffic, in particular in summer.
The low incidence of accidents demonstrates the low risk involved and the high stability of the cliffs
of the eastern side.
The development of this area as a high density residential area could bring with it other problems that
might affect the Talus slope. Amongst these are:-
• Risk of fire.
• Predation of indigenous fauna by feral cats and dogs.
• Encroachment by alien species of flora and fauna.
• Cliff stabilisation.
• Rockfall netting and fencing.
• Accessing of the site by residents of nearby areas.
4.5 Conservation Direction
The Talus Slopes comprise a unique and important habitat in Gibraltar, especially since the isthmus’
sandy habitat has been almost totally urbanised. Together with the Great Sand Slopes, they are a refuge
for sand-loving and sand-dwelling species of flora and fauna. With this in mind, part of the action plan of
the isthmus habitat is not only to conserve what is left of it but also to transfer species of flora and fauna to
the Talus and Great Sand Slopes. This has already been achieved in part by the restoration of the Great
Sand Slopes with the re-seeding of native species, in particular those that were scarce or had become
extinct. In the same way invertebrate species should be transferred to both these habitats.
Conservation measures should include:-
• Re-seeding and transfer of key plant species from isthmus habitat.
• Introduction of key invertebrate species and transfer from isthmus habitat.
• Removal of invasive species, especially Carpobrotus edulis x acinaciformis, Agave americana and A.
ghiesbreghtii.
• Regular monitoring of flora and fauna.
• Prohibition of destructive activities such as motor cycle scrambling.
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5. GREAT SAND SLOPES
Figure 7: The Great Sand Slopes forming a buttress against the east cliffs (L. Linares).
The Great Sand Slopes form an extensive area of approximately 45ha of wind blown sands that extend
from above Sandy Bay in the south to Catalan bay to the north. These sands, which contain a high percentage
of uniform quartz grains, originated outside Gibraltar, since there is almost no quartz bearing strata
on the Rock. The sand slope was formed during the Quaternary period when the area to the east was
a dry sandy plain, by wind action that deposited the sand upon existing scree breccias and boulder conglomerate
(Rose & Rosenbaum, 1991).
At one time the Talus slopes to the north and south, together with the Sand Slopes, formed one contiguous
mass. However, the Catalan Bay and Sandy Bay quarries, opened by the Admiralty in 1895 to provide
material for the Dockyard extensions, isolated the Great Sand Slopes from the Talus slopes. The talus
extremities, located below the major cliff faces below Spyglass and Rock Gun seem to have accumulated
the largest quantity of rock boulder material. This has formed the conglomerate scree breccias, but is still
covered by a sandy layer. The central portion, where the Great Sand Slopes are located, has undergone
less rock deposition from above, but has a greater accumulation of windblown sands, substantially differentiating
this geological structure from the adjacent Talus slopes. A borehole on the lower part of the slope
indicated at least 40m of sand present at this location (Rose & Rosenbaum, 1991).
Drawings from the 1800s depicting Catalan Bay show the Sand Slope almost devoid of vegetation, with
goat herds present. The devastating effects that goats have on the vegetation are well documented (See
Chapter 6), and the presence of these animals on the Slopes would have caused extensive environmental
damage in the form of habitat loss and erosion.
In the late 1970s the Public Works Department of the Gibraltar Government opened a quarry at the base
of the Sand Slopes, with the intention of using the sand for building material. The quarrying was soon
stopped for the operation was dangerously undercutting the slope and rendering it unstable, placing in danger
the stability of the Water Catchments. The operation was transferred to the top of the slope at the base
of the cliff where machinery was installed for the removal and transfer of the sand down the slope.
Problems were immediately encountered, for the sandy material at the base of the cliff was intermixed with
boulders, some extremely large, that had fallen from above. Eventually the quarry was deemed unviable
and closed down, but by then a substantial amount of sand had been removed that created a terrace over
100m long and 10m wide. This venture has had the unplanned consequence of creating a rock catchment

area that traps falling rocks and has rendered the lower stretch of highway between the Caleta Hotel and
Sandy Bay relatively safe. The quarry has also provided a level area that has been recolonised by wildlife.
In the early 1900s most of the Great Sand Slopes were covered with corrugated iron sheets that formed
a Water Catchment area. At the time a number of plant species were lost, and the disappearance of the
Black Wheatear Oenanthe leucura from Gibraltar most likely resulted from the loss of this habitat. It is likely
that certainly prior to the grazing of the site by goats even before the catchments were being considered,
the natural community of the site included species that frequent sandy habitats in the region. These may
have included plants such as the Sage-leaved Cistus Cistus salvifolius, the Myrtle Myrtus communis, and
the White Broom Retama monosperma, reptiles such as the Spiny-footed Lizard Acanthodactylus erythrurus,
and other birds such as the Spectacled Warbler Sylvia conspicillata and the Dartford Warbler Sylvia
undata. The water catchments were divided into two areas, with the north the responsibility of the Gibraltar
Government and the south of the MoD. This structure was rendered obsolete with the advent of desalination
plants. The removal of the Water Catchments required the stabilisation of the underlying sands.
GONHS was consulted and a meshed netting of degradable material, that would allow plants to grow
through, was installed upon removal of the sheets. GONHS, through the Gibraltar Botanic Gardens, was
also contracted to reseed the slopes, and this was done using sand-loving native grasses and shrubs.
An extensive area above the southern end of Catalan Bay that did not form part of the water catchments
was, in the past, planted to stabilise the sands. Rooikrans Acacia cyclops and the Canary Island Date Palm
Phoenix canariensis were used extensively in this area as well as the Century Plant Agave americana and
Spineless Yucca Yucca elephantipes, all non–natives. The Acacia and the Agave in particular are potentially-damaging
invasive species.
5.1 Current Status
5.1.1 LEGAL STATUS
The Great Sand Slopes are currently not designated as protected areas under local legislation, but several
species of flora and fauna found on the slopes are covered by the ‘Nature Protection Ordinance 1991’.
The Great Sand Slopes are part of a candidate special area of conservation (cSAC) under the Habitats
Directive. This habitat is listed under a Malcolmeitalia (dune Malcolmia annual-herb community) dune
grassland (NATURA 2000 code: 2230; CORINE 91:16.228) on a stabilised sand dune. It is regionally
important, as sandy littoral zones have been urbanised throughout coastal Andalusia, and as a geological
and landscape feature is of global importance.
5.1.2 MANAGEMENT, RESEARCH AND GUIDANCE
The Great Sand Slopes provided a unique opportunity for fulfilling one of the main requirements of the
Biodiversity Convention, under Article 8(f) which states:-
“Rehabilitate and restore degraded ecosystems and promote
the recovery of threatened species, inter alia, through the
development and implementation of plans or other management
strategies”
Representations by GONHS led the Gibraltar Government to agree to replant the slopes in order to stabilise
the exposed sand once the sheeting was removed. Seeds were collected locally, and in adjacent
coastal habitats for those species where enough seeds were not available locally, or which were locally
extinct, and re-seeding began in 1997.
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Table 8: Species used for seeding the Northern Sand Slopes.
Common Name Scientific Name
Wild Leek Allium ampeloprasum
Marram grass Ammophila arenaria
Snapdragon Antirrhinum majus
White Asphodel Asphodelus albus
Spiny Broom Calicotome villosa
Dwarf Fan-palm Chaemerops humilis
Cocks Foot Dactylis glomerata
Wild Carrot Daucus carota
Squirting Cucumber Ecballium elaterium
Sea Holly Eryngium maritimum
Giant Tangier Fennel Ferula tingitana
Yellow-horned Poppy Glaucium flavum
Hoary Mustard Hirschfeldia incana
Tree Mallow Lavatera arborea
Sweet Alison Lobularia maritima
Wild Olive Olea europea
Gibraltar Restharrow Ononis natrix
Sea Orlaya Orlaya maritima
Cottonweed Otanthus maritimus
Silver Parynochia Parynochia argentea
Smilograss Piptatheum miliaceum
Buck's-horn Plantain Plantago coronopus
Dock sp. Rumex sp
Sweet Scabious Scabiosa atropurpurea
Silver Ragwort Senecio bicolor
Pink Mediterranean Catchfly Silene colorata
Sticky Catchfly Silene nicaeensis
Blunt-leaved Catchfly Silene obtusifolia
Natural, wind-blown seeding must also have taken place and surveys in 1998 and 1999 revealed a total
of 59 and 83 species respectively, with an overall cover of 60%, ranging from up to 80% in some areas
down to 10% in places where the matting had not been adequately fixed and had compromised the development
of the plants.
Some alien species that were found in the adjacent areas to the catchments have also begun to invade
the open areas of the Sand Slopes. Particularly worrying is the Rooikrans Acacia cyclops and to a lesser
extent the Century Plant Agave americana. The former has the potential to cover large areas of the slope
smothering low shrubs and plants, and should therefore be included in a species eradication and control
plan under this Biodiversity initiative.
Table 9: Alien species found growing on the Sand Slopes.
Common Name Scientific Name
Rooikrans Acacia cyclops
Golden Wreath Wattle Acacia saligna
Century Plant Agave americana
Green Century Plant Agave ghiesbreghtii
Tree Aloe Aloe arborescens
Hottentot Fig Carpobrotus edulis x acinaciformis
Red Gum Eucalyptus camaldulensis
Shrub Tobacco Nicotiana glauca
Prickly Pear Opuntia ficus-indica
Bermuda Buttercup Oxalis pes-caprae
Cape Wattle Paraserianthes lophantha
Canary Palm Phoenix canariensis
Spineless Yucca Yucca elephantipes

A few years later, the Ministry of Defence decommissioned their section of water catchments. Re-seeding
was successfully carried out in a similar fashion to the previous operation. As part of this endeavour a
specific condition for the acceptance of this work in relation to the vegetation cover required the following:
“Criteria for acceptance of the vegetation.
The vegetation will be adjudged to have successfully established
on the basis of plant density/percentage coverage and on
the diversity of species as defined below:
After two years average, coverage should be 60% with no areas
less than 40%. Diversity will be measured by selecting 10 in
number 15m 2 plots at random; these should contain at least 10
species. 50% of the plots should contain at least 15 species. If
these criteria are not met then selective reseeding of deficient
areas should be undertaken.”
Taken from terms of reference by Gifford & Partners in Cortés et al. (2000).
Five surveys were carried out between April 2002 and December 2004, and a notable increase in
species diversity was detected except in the autumn survey when many plant species are dormant. Most
of the criteria were met except for additional seeding in four areas that was carried out during the 2004/2005
winter. The GONHS now carries out an annual survey in late spring to monitor the flora and fauna of the
Great Sand Slopes.
In addition to the removal of the Water Catchment and the reseeding of the slopes, the MoD installed a
complex network of strong fencing, as protection against rockfalls. Three lines of defensive fencing were
installed to protect the residential complex of Both Worlds that lies immediately below the slope.
This particular project is an example of the work that GONHS has carried out in relation to some of the
requirements of the Biodiversity Convention.
5.2 Current Factors affecting Habitat
Acacia cyclops, an alien invasive, is affecting the long-term well-being and integrity of the habitat on the
Great Sand Slope.
5.3 Current Action
No action is being taken at present, but a habitat management programme to eradicate Acacia cyclops
is urgently required before the problem worsens.
5.4 Threats
Potential and existing threats include:
• Risk of fire.
• Expansion of the invasive shrub Acacia cyclops.
• Urban development of the base of the Sand Slopes leading to the loss of some habitat and the installation
of extra rockfall defences.
• Feral cats and dogs.
The risk of fire on any habitat in Gibraltar is great due to the dry conditions that prevail during the summer
and early autumn. The situation on the slopes is aggravated because the composition of the sandy
substrate is extremely porous and does not hold moisture for any length of time. Therefore the vegetation
tends to dry out quicker than similar vegetation on limestone habitat. However, fire is a natural element of
grassland ecosystems and is important for their long-term survival, preventing encroachment by woody
plants. It is nevertheless essential that fires do not occur too often, that they do not affect the area during
those times of year when the fauna is breeding and that they only affect part of the slopes on any one
occasion.
In late summer 2005, youths playing with flares on the lay-by at the base of the Sand Slopes, allegedly
set fire to the vegetation (See fig.8). The northern area was affected as the flames quickly spread
upwards, burning the remnants of the matting and the wooden framework that had been left in place after
the removal of the corrugated sheeting. With the first rains of the year, most of the vegetation returned, but
several species were lost, including Otanthus maritimus, which had been established following local extinc-
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tion. Among the survivors were Olive bushes that re-sprouted from the roots and the invasive Golden
Wreath Wattle Acacia saligna, but the Rooikrans Acacia cyclops was killed outright. Future surveys will be
required to assess the area, with a provision for reseeding any species that may have been lost as a result.
Figure 8: Great Sand Slopes, autumn 2005 showing the burnt section at the top of the picture.
The alien Acacia cyclops is slowly invading the sand slope areas where the water catchments have
been removed. This Acacia stand was originally planted above the Caleta Hotel, in a section of the sand
slopes that did not form part of the water catchments. Alongside this area, a section of water catchments
blew off in a strong westerly gale in 1976, and immediately new Acacia plants established themselves. This
is again occurring on the exposed sand slopes and within two years of the removal of the catchments,
plants had established themselves widely. Most of this new growth is restricted to the lower margins of the
Great Sand Slopes, but it may only be a question of time before this invasive species spreads to the upper
reaches of the slope.
Figure 9: The burnt area of the Great Sand Slopes, spring 2006 with fresh growth.

There is at present a development boom in Gibraltar, and the eastern side of the Rock has not escaped
the attention of developers. A new residential development, ‘Little Genoa’, is being built in an area between
Catalan Bay and the Caleta Hotel. This area is notoriously dangerous, for most of the recent rockfalls that
have taken place in this area in the last 50 years have occurred here. Even Catalan Bay’s great rock icon,
‘La Mamela’ must have originated at the top of the Rock, and crashed through this spot. Another speculative
residential project, south of the Caleta Hotel was fortunately rejected by the Development and Planning
Commission, but there are indications that the Sandy Bay residential area of ‘Both Worlds’ may seek to
extend their housing complex.
Any development of the coastline from eastern beach to Sandy Bay would probably mean further rockfall
protection measures, including anchoring of loose or potentially unsafe areas of the cliff, netting and
other works, involving grouting and concreting large tracts of the cliff face. This is unreasonable, unsightly
and costly and the implications should be considered fully should any future development plans be proposed
to the Development and Planning Commission.
The presence of Feral cats seems to be a problem that has increased in recent years. Feral dogs have
also been found in the site in the past. Cat culls used to occur at regular intervals, but now seem to occur
only when a problem that is highlighted by the general public or when the potential transmission of diseases
to humans becomes a concern. Only then do we see a concerted effort to eliminate cats in particular areas,
and even then there is opposition from sectors of the public and indeed the Cat Welfare Society, who
believe that feral cats deserve a place in the wild. They are an alien, damaging species that do not have
a legitimate role within our wildlife communities.
A pack of dogs roamed the sand slopes in the late 1900’s and obviously managed to survive in the wild.
They had to be shot since they posed a menace to members of the public. A survey in the 1990’s using
hidden cameras to assess the fox population of the Nature Reserve after rabbit carcasses were discovered
in several places, revealed a feral dog to be the culprit. The dog was of the breed known as ‘podenco’,
used by hunters in Spain, and had probably escaped from its owners. A dog of this breed was seen roaming
the sand slopes in April 2006.
5.5 Conservation Direction
This recent history of the Great Sand Slopes is certainly a success story, but they need to continue to
be monitored closely.
Measures to be taken:
• Removal of invasive species, especially Acacia cyclops, Carpobrotus edulis x acinaciformis and Agave
americana. (See Alien Invasive action plans).
• Removal of feral cats.
• Re-seeding where necessary and transfer of key plant species from the Isthmus and Talus habitats.
• Introduction of key invertebrate species and transfer from the Isthmus and Talus habitats.
• Introduction of other plant species of sandy habitats in Cadiz Province, Spain.
• Re-introduction of the Black Wheatear and the Spiny-footed Lizard.
• Regular monitoring of flora and fauna.
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6. THE ISTHMUS
Figure 10: Remnants of the Isthmus habitat on the North Front Aerial
Farm and at the foot of the North Face.
The Isthmus is the narrow stretch of land up to three metres above sea-level and three kilometres long
between the Sierra Carbonera and the North Face of the Rock that links the Rock to the mainland. It is
was formed by the deposition of sand brought down by the rivers Palmones and Guadarranque in the Bay
of Gibraltar to the west, and the river Guadiaro to the east. The prevailing easterly and westerly winds
formed an intricate low dune system interspersed by hollows that flooded in the winter. The underlying
geology is composed mainly of marine sands and clays dipping towards the Rock, forming an aquifer that
lies relatively close to the surface in the area of North Front, where several wells are sited. The vegetation
of the area was composed of low-lying grasses and sedges together with other shrubs and bushes including
the Bitter Fennel Foeniculum vulgare and Dittrichia viscosa.
The isthmus is Gibraltar’s only land connection with Spain. Historically, it was not an ideal place for a
settlement, since it was exposed to the elements and did not afford the protection that could be found a few
hundred metres away within the City walls, under the shelter of the Rock itself. It did provide some residents
with pasture for their livestock and enabled some cultivation of crops in the few sheltered spots
(Portillo, ca.1620). Under the British occupation the isthmus remained undeveloped, since it was in the
direct line of fire from the Spanish fortifications and therefore too dangerous. Known as ‘no-man’s land’, it
remained in a wild natural state throughout the 18 th and 19 th centuries. Border posts were located at either
end of the Isthmus and the intervening land was referred to as the Neutral Ground.
A relaxed political atmosphere with Spain saw the development of the isthmus into a recreational area
with the establishment of the Victoria Gardens, sporting facilities and a horse racecourse, but with the

advent of the second world war the airfield was built on the isthmus and extensive works began, resulting
in the development of most of the isthmus area south of the Spanish border into airport infrastructure which
was extended to include residential areas for the military. The only remnants of the isthmus habitat that
remained were garden areas at North Front residential area, a tract of land that was set-aside as a cemetery
for the burial of the local inhabitants and another section adjacent to Devil’s Tower and the North Face
of the Rock, which was developed into the aerial farm. Even these areas have slowly shrunk as more and
more of the land has been utilised, with the resulting loss in the habitat and biodiversity.
6.1 Current Status
6.1.1 LEGAL STATUS
What is left of the isthmus habitat is composed of small parcels of land that form the remnants of a
unique dune and slack habitat. None of these have any direct environmental protection, but many of the
species occurring there are protected under the ‘Nature Protection Ordinance, 1991’.
6.1.2 MANAGEMENT, RESEARCH AND GUIDANCE
The remnants of the isthmus habitat contain an interesting community of flora and fauna that is not
found elsewhere in Gibraltar and is rare in the region.
Access to the largest remaining area of the isthmus, the MoD Aerial Farm, was formerly restricted, but
following the recent removal of the aerials, GONHS surveyed the area during three visits in 2005. Several
interesting plant and invertebrate species were found there.
6.2 Current Factors affecting Habitat
Western beach is being encroached upon by the extension of bathing facilities that have recently been
erected. Rubbish deposition and its use as a toilet by beachgoers are also polluting the sand dunes.
The North Front Cemetery has no environmental development plan, and therefore any free area is
taken over by grave and mausoleum developers. In the last fifteen years, the last empty sectors of the
Cemetery have been developed, including the vegetated northeastern corner where trees and shrubs have
been removed to allow for extra graves. No dimension restriction for graves or other guidelines seem to
apply and a lack of proper planning has led to areas becoming a concrete blanket as grave after grave is
built with no room between each for landscaping. Recent moves to refurbish the Cemetery paths may not
resolve this completely and a proper management plan is required.
The Aerial Farm was handed over to the Gibraltar Government in 2005. The area still has a lot of old
cable anchor points and concrete bases and the remains of a large aerial in the centre. The southern sector
is used as a car park for a Security firm and was extended for use as the beach car park in the summer
of 2005, in lieu of the original car park that is being developed as part of the eastside development. After
the summer, cars from Bassadone Motors were allowed to park there, covering a large part of the area.
The aerial farm below the North face, south of Devil’s Tower Road, has been left untouched, as it is a
high-risk rockfall area.
6.3 Current Action
None, with the exception of occasional floral and faunal surveys.
6.4 Threats
Western Beach is under threat from a proposed reclamation project, for car parking facilities for the private
company Bassadone Motors. This would extend the land area adjacent to the north side of the runway.
Depending on the final configuration, this may have an adverse effect on the sand dune habitat if the
beach disappears in part or completely.
Currently the North Front Cemetery is an environmental disaster. It is practically a concrete extension
of the runway, with its few green corners fast disappearing. Apart from posing a threat to its special fauna
and flora, the Cemetery is also visually unattractive. Much could be done to improve the cemetery, both
for wildlife and visitors.
The aerial farm is now a car park and the remaining area is under threat for use for parking facilities for
beach users in the summer and Bassadone’s cars during the rest of the year. The east side reclamation
project will put further development pressure on this unique area.
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The south aerial farm is under no apparent threat and should be conserved immediately.
6.5 Conservation Direction
The two large areas of Isthmus habitat that remain on either side of Devil’s Tower Road, together with
the Western beach sand dunes, require protection.
The North Front Cemetery requires an environmental management plan to ensure that the requirements
of the area as a cemetery are compatible with sound environmental practices and that the area is kept in
a condition that will be agreeable to the general public whilst ensuring that the natural environment is not
adversely affected.
The Aerial Farm could provide space as a new Cemetery if proper environmental management and
landscaping would form part of the general plan for the area.
The habitat adjacent to the North Face could be established as a conservation area, under the Nature
Protection Ordinance, since rockfalls make it too dangerous for development. Some re-seeding and
translocations could be carried out here.
7. SOUTH DISTRICT
Figure 11: View of part of the South District of Gibraltar.
The South District, here regarded as the area of Gibraltar south of the Alameda Gardens, but not including
the Upper Rock, holds a variety of habitats such as open-ground pseudosteppe, garigue and some
small pockets of low maquis and woodland. It is especially important for cliff habitats, including an important
habitat in Annex I of the Habitat Directive under ‘Vegetated sea-cliffs of the Mediterranean coast’ especially
those with endemic Limonium spp. A large proportion of the South District consists of residential
urban and garden areas. However, the South District includes several distinct areas that have been individually
surveyed and classified according to their biodiversity importance, threats and action required.
These are:
• Windmill Hill
• North Gorge/Buena Vista
• Jacob’s Ladder
• Europa Point Foreshore
• Governor’s Cottage Camp
• Hole in the Wall
• Beefsteak area
• Europa Flats
• Camp Bay
• Little Bay
• Rosia

7.1 Current Status
7.1.1 WINDMILL HILL:
This is a Ministry of Defence area that is regularly used for military training purposes, with two shooting
ranges, two communication aerials enclosures, an assault course, and abandoned buildings used for training
purposes in an area called Buffadero village.
Windmill Hill is a flat limestone raised beach for much of its northern half, sloping to the south and bordered
on three sides by vertical cliffs. The vegetation consists mainly of low grasses and herbaceous plants
with lentisc and olive bushes on the southern slopes and the more sheltered areas. It holds a distinctive
community of plants, many of which are found only at this location. A major stronghold for the Barbary
Partridge, where approximately ten pairs breed successfully, it is also the most important stopover location
in Gibraltar for migrant passerine birds, with a database, kept by GONHS, dating back some 45 years
(Cortes, 1996).
It is afforded protection as a MoD Conservation Area, and has its own specific action plan (In Bensusan
& Perez 2003).
7.1.2 NORTH GORGE / BUENA VISTA:
The North Gorge area has impressive geological limestone karst features that are unique to the region.
It is heavily faulted, with majestic ivy-clad cliffs interspersed with numerous fissures, some of which develop
into caves, several containing archaeological remains. Bounded on either side by the Windmill Hill and
the Buena Vista cliffs, the gorge itself is humid receiving limited amounts of sunlight. The floor of the gorge
is level and most of the area has been built upon, although most buildings are now derelict. The MoD has
its water desalination plant installation at the southern end, the Gibraltar Pistol Shooting Club has its premises
on what used to be a workers hostel and the adjacent site is an open garage full of derelict cars. The
gorge continues north through a maze of derelict buildings above which stands the Naval Hospital and a
new development called The Cliftons. Europa Road runs along the upper gorge and to the east are several
residential cottages and another new development called Highcliffe House. The corner below Devil’s
Bellows is heavily fractured with large limestone boulders strewn around and is densely vegetated with the
remnants of ‘Mediterranean Arborescent Matorral’, Matorral with sweet laurel Laurus nobilis, which is listed
as Priority habitat under Annex I of the Habitats Directive and requires the designation of a Special Area
of Conservation (SAC).
There are numerous interesting trees and plants including several Dragon trees Dracaena draco with
one particularly old specimen, one of Gibraltar’s three known Round-leaved Oaks Quercus rotundifolia,
many Hawthorn bushes Crategus monogyna, Sweet Laurel Laurus nobilis, and the most spectacular ivy
Hedera helix clad cliffs in the region. Several interesting cliff dwelling species of plants occur including the
Gibraltar Candytuft and the Caper Capparis spinosa, both protected under the Nature Protection
Ordinance.
The caves in this area require protection for their historical and natural heritage value.
The Buena Vista site lies to the west of North Gorge and consists mainly of cliffs that are more exposed
to the sun. These cliffs hold an important plant community that includes Giant Tangier Fennel Ferula tingitana,
Gibraltar Sea Lavender Limonium emarginatum, Caper Capparis spinosa and a unique population of
the rare white form of the Fragile Bellflower Campanula velutina. Blue Rock Thrushes breed on these cliffs.
7.1.3 JACOB’S LADDER:
This vegetated corner to the west below Windmill Hill, bordered by Europa Road, contains a dense
maquis habitat that is quite unlike anything found in the South District. Sheltered from the strong levanter
but exposed to the strong westerly winds, the area is a haven for many interesting plants including orchids,
and is used as shelter and a stopover site by migrant birds and as a breeding and roosting site by Barbary
Partridges.
7.1.4 FORESHORE:
The Europa Foreshore is the narrow strip of land that slopes gently into the sea immediately below the
walls and cliffs at Europa Point, bordering the Strait of Gibraltar. It was held by the MoD and used as an
aerial farm with a small residential area in the centre. The area is now in the possession of the Gibraltar
Government and the residential area has been incorporated within the local housing stock.
The Foreshore is exposed to the elements, in particular the eastern sector that is swept by the easterly
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gales and salt spray, and is unsuited to all but the hardiest of plants, including the Gibraltar Sea Lavender
Limonium emarginatum, a salt-resistant species with its stronghold in this habitat. It comes under Annex I
of the Habitat Directive under ‘Vegetated sea-cliffs of the Mediterranean coast’ especially those with
endemic Limonium spp. and therefore requires the designation of Special Area of Conservation (SAC).
Unfortunately it also harbours many of Gibraltar’s alien species of flora that have escaped from the gardens
of the residential area and have become naturalised in this zone (see Chapter 6).
7.1.5 GOVERNOR’S COTTAGE CAMP:
The area in question runs north-to-south along the base of the east cliffs bordering Windmill Hill as far
as the area north of the Refuse Incinerator. Governor’s Cottage Camp is in a derelict state, as are most of
the buildings to the north, including the old Refuse Incinerator.
The whole area is a haven for alien, invasive species of plants, and has few remnants of the original
native flora and fauna. This is with the exception of the cliffs, whose flora includes Gibraltar Candytuft Iberis
gibraltarica, Gibraltar Sea Lavender Limonium emarginatum, and Joint Pine Ephedra fragilis, the latter a
host species for the endemic beetle, Buprestis (Yamina) sanguinea calpetana. Nesting birds include
Peregrine Falco peregrinus, Little Owl Athene noctua and Blue Rock Thrush Monticola solitarius.
7.1.6 HOLE IN THE WALL:
The area was once open, garigue habitat with low-growing grasses and shrubs that suited many native
species of plants and was a favourite feeding area for the Barbary Partridge and Blue Rock Thrush. It contained
some alien species that included the Prickly Pear Opuntia ficus-indica. In the last decade, for reasons
as yet unknown, this species of cactus has become a serious invasive that has smothered all but the
resistant Dwarf Fan Palm Chaemerops humilis, which still manages to grow through this mass.
This area also contains a rock quarry that is used as a refuse dump, which is frequented by the Yellowlegged
Gulls and a group of Barbary Macaques.
There is also a promontory occasionally used by the Clay Pigeon Shooting Club that is in an abandoned
and disgraceful state, with cartridges strewn all over the site and on the cliffs below.
7.1.7 BEEFSTEAK AREA:
This is the narrow strip of land below the southern cliffs of Windmill Hill and bordered by Europa Road
where Beefsteak cave is situated. Mainly composed of a scree slope containing tunnelling debris, the area
adjacent to the cliff harbours an interesting community of invertebrates and flora that benefit from the southfacing
location of the area.
The unsightly, disused pipeline that runs along the cliff base all the way to the Refuse Incinerator mars
the area.
7.1.8 EUROPA FLATS:
These consist of the whole area around Europa Point, which like Windmill Hill Flats is a raised beach.
Mainly urbanised, the area also contains gardens and small pockets of natural habitat, amongst which is
the viewing platform at Europa Point commonly referred to as the Mound, which harbours many interesting
native plant species.
The area around the Nun’s Well was landscaped for the opening of the Mosque, but the plant species
selected were not suited to the harsh climatic conditions and perished.
7.1.9 CAMP BAY:
This area is unique in that the steep slope bordering the Buena Vista cliffs is composed of mudstones
and shales. Surrounded by limestone cliffs, the area has an interesting community of plants and the slope
is heavily vegetated with maquis consisting mainly of Lentisc and Olive scrub.
7.1.10 LITTLE BAY:
Formed and extended by a former rock quarry, the area is also surrounded by majestic limestone cliffs
with an important and extensive plant community including the Gibraltar Sea Lavender. The substrate of
the area is mainly composed of limestone debris; remnants of the quarrying operation. Vegetation in the
area is limited to the cliff base.
7.1.11 ROSIA:
This area lies below the fortification walls and the Parson’s Lodge cliffs, and consists of a narrow strip

of land with minimal vegetation cover but including the Gibraltar Sea Lavender. Within the Parson’s Lodge
site is an interesting area with natural herbaceous vegetation and shrubs. The shoreline of this area and
is dealt with below under the Inter-tidal zone and Marine habitats.
7.2 Current Factors affecting Habitat
7.2.1 WINDMILL HILL:
The spread of several invasive species is seriously affecting the area. The most serious is the Kikuyu
Grass Pennisetum clandestinum that spread from the former Navy Satellite Installation into the adjacent
area. It has also been found growing around the Rifle Shooting range and along the roadway leading
south-west. Others include the Hottentot Fig Carpobrotus edulis x acinaciformis, and the Tree Aloe Aloe
arborescens.
Works by the MoD in this site, and military exercises potentially damage the ecology if, as often happens
these are carried without consultation and due care and/or at sensitive times of the year.
Tentative plans for a power station and wind turbines in the area are of extreme concern as both would
impact strongly on the landscape value of the site and potentially have serious effects on the ecology and
on migratory birds.
An artificial pond that was constructed in the early 1980s was damaged several years ago and is in need
of restoration.
7.2.2 NORTH GORGE / BUENA VISTA:
Several development projects have and are being carried out that are affecting the habitat of the area.
The most serious factor is the alleged need for cliff stabilisation around every development under construction,
with meshing, scraping and concreting severely affecting the important cliff habitat.
A large urbanisation development project is planned that could seriously affect the integrity of the whole
area.
Much of the area requires a geological survey to assess the suitability for high-rise buildings in some
locations.
7.2.3 JACOB’S LADDER:
No current factors are affecting the habitat of this area.
7.2.4 FORESHORE:
Extensions to the residential area and the indiscriminate disposal of building debris, surplus domestic
appliances and refuse in the surrounding area is contaminating the soil and smothering the native flora.
One of the residents has installed a chicken coop and released rabbits in the area.
Several species of alien invasive flora can be found at this location, among which the Agave, Hottentot
Fig and Prickly Pear have seriously extended their ranges, smothering a large area.
7.2.5 GOVERNOR’S COTTAGE CAMP:
Extensive colonisation by alien invasive plants in the past is seriously affecting the habitat of this area.
Species include the Aloe, Hottentot Fig, Agave and the Cape Ivy. Very little of the original native habitat
remains, other than on the cliffs above, where cliff stabilisation works have recently been carried out.
This beautiful area of coastline with its magnificent sea cliffs was once used as a dumping ground and
is now an eyesore. The cliff habitat is in many places covered with the remains of scrap that are seriously
affecting the well-being of the cliff habitat. Illegal dumping in the area remains a problem. The cliff area
is singularly unattractive in the areas where it is littered with all sorts of items. The old Car Chute and the
dump site opposite the Refuse Incinerator is still used for illegal dumping as can be seen by the amount of
material that is strewn around the cliff edge, affecting the native plants growing there.
There are derelict cars on the roadway leading up to the Refuse Incinerator and Feral Chickens running
loose in the area.
7.2.6 HOLE IN THE WALL:
The habitat has been devastated by the invasive Prickly Pear, which has smothered most of the natu-
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ral vegetation in the area. The area is also affected by the foraging habits of a group of Barbary Macaques.
Indiscriminate dumping over the cliffs of material that is not allowed at the refuse tip is seriously affecting
the cliff habitat and the marine environment in this area. The whole area is a smelly eyesore, albeit with
the magnificent backdrop of the eastern side cliffs.
The shot cartridges at and below the Clay Pigeon Shooting Club cover extensive areas of the cliffs that
smother the native plants. They are also affecting the marine environment.
There is also a mattress burning compound, spewing noxious fumes into the atmosphere, which is littered
with the remaining metallic spring skeletons, many dumped over the cliffs that can be seen on the
rocks below. This is compromising and polluting the cliff habitat.
7.2.7 BEEFSTEAK AREA:
No factors are currently affecting the habitat.
7.2.8 EUROPA FLATS:
The area around the Nun’s Well is commonly used by car and motor cycle riders for off-roading, which
destroys natural vegetation and does not allow it to regenerate. This practise regularly takes place on the
Europa Mound, destroying the vegetation and quickly eroding the paths.
7.2.9 CAMP BAY:
An alien invasive plant, the Cape Wattle Paraserianthes lophantha, is suffocating the native vegetation
on the slope. This species is included in Chapter 6 (Alien, Invasive and Pest species action plan).
The mudstone slope is unstable and requires shoring up with a strong retaining wall before there is a
serious landslide that will obviously affect the integrity of the slope’s habitat.
A Feral Cat colony is established at this site, compromising the wildlife in this habitat. The cats are regularly
fed by cat lovers.
7.2.10 LITTLE BAY:
The slopes around the area need to be cleared of rubbish and litter. A colony of Feral Cats is also located
in this area.
7.2.11 ROSIA:
No factors are currently affecting the habitat.
7.3 Current Action
7.3.1 WINDMILL HILL:
The alien invasive plants in this area are currently being monitored and those requiring attention are
being tackled by GONHS in collaboration with the MoD.
7.3.2 NORTH GORGE / BUENA VISTA:
The Caves and Cliffs section of GONHS is currently monitoring and surveying the caves in the area and
have recently uncovered the entrance to Judge’s Cave that had been buried under rubble.
No action is currently being taken on the habitat of the area, although there has been much objection
by GONHS to the cliff stabilisation that continues to take place.
7.3.3 JACOB’S LADDER:
No action is currently being taken.
7.3.4 FORESHORE:
No action is currently being taken, although the elimination of several of the alien invasive plants is a
requisite under its specific action plan.
7.3.5 GOVERNOR’S COTTAGE CAMP:
No action is currently being taken, although the elimination of several of the alien invasive plants is a
requisite under its specific action plan.

7.3.6 HOLE IN THE WALL:
No action is currently being taken, although the elimination of several of the alien invasive plants, especially
the Prickly Pear, is a requisite under its specific action plan.
7.3.7 BEEFSTEAK AREA:
No action is currently being taken.
7.3.8 EUROPA FLATS:
No action is currently being taken.
7.3.9 CAMP BAY:
No action is currently being taken, although the elimination of the alien invasive plant the Cape Wattle
and of the Feral Cat is a requisite under its specific action plan.
7.3.10 LITTLE BAY:
No action is currently being taken.
7.3.11 ROSIA:
No action is currently being taken.
7.4 Conservation Direction
7.4.1 WINDMILL HILL:
The suggestions and recommendations in Bensusan & Perez (2003) should continue to be addressed.
These would include implementation of a formal management plan for the area. In spring 2005 a team from
Defence Estates in UK came to assess the incorporation of MoD land within the Habitats Directive candidate
Special Area of Conservation (SAC) and supported the recommendation. In relation to that part of
Windmill Hill under MoD control (i.e. south of the parade ground), the re-instatement of the MoD
Conservation Group would make a very positive contribution.
Consideration of the area as a site for the location of wind turbines must be resisted in view of their
impact on migratory birds which focus on this area.
The plans for a power station should be reviewed and the site changed to the Europa Advance area
below the cliff, where visual impact and effect on migratory birds, as well as of the effluent plumes, would
be greatly reduced.
7.4.2 NORTH GORGE:
Monitor the habitat and investigate the extent of the new proposed development, and seek an EIA.
Ensure the survival of the Oak tree and Dragon Trees. Designate the north-eastern sector (between
Windmill Hill Road and Highcliffe House) as a conservation area for its valuable Bay Laurel and Hawthorn
stands.
7.4.3 JACOB’S LADDER:
Monitor the development of the habitat and survey the area for flora and fauna.
Continue migrant bird surveys in this area in conjunction with Windmill Hill.
7.4.4 FORESHORE:
The establishment of an Alien Invasive eradication programme to eliminate the large quantity of invasive
plants found there.
The removal of all building debris, refuse and materials dumped around the residential and adjacent
areas.
Removal of the Chicken coop and elimination of feral rabbits.
Requires designation as a conservation area for its unique, large population of the Gibraltar Sea
Lavender, linked to its interesting Inter-tidal zone and the Europa Reef.
7.4.5 GOVERNOR’S COTTAGE CAMP:
The area in question could continue to be used as an industrial area, and extended to absorb a relocat-
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ed power station, but any development in the area should have aesthetic qualities that should blend in harmony
with the scenic beauty of this area of Gibraltar.
Chicken coops and derelict cars in this area should be removed.
The old car chute gateway and concrete slope should be removed and the original wall rebuilt.
The dumping hole opposite the entrance to the Refuse Incinerator should be sealed and its associated
structure removed.
The cliffs around the dumping area should be cleared of scrap, mangled metal debris and refuse to
allow natural vegetation to regenerate.
7.4.6 HOLE IN THE WALL:
The establishment of an eradication programme for the removal of the Prickly Pear and other invasives
from this area.
Embellishment of the Clay Pigeon Shooting Club compound and removal of refuse and cartridges from
the surrounding area.
Removal of all scrap and debris from cliff areas, and erection of signs prohibiting dumping.
Establish an environmentally friendly method of mattress disposal and restore the site back to its natural
state in order to improve the habitat.
Assess the future of the Barbary Macaque group established at this location.
7.4.7 BEEFSTEAK AREA:
The area, habitat and aesthetic value of the site would benefit from the removal of the disused pipeline,
and associated concrete bases and structures.
7.4.8 EUROPA FLATS:
The area around the Nun’s Well requires landscaping with salt-resistant species of shrubs and plants.
The area should be protected from encroaching vehicles.
The area around the Europa mound requires embellishment with the addition of salt-resistant native
plant species and the removal of alien species.
7.4.9 CAMP BAY:
The area requires the urgent removal of the invasive plant Paraserianthes lophantha from the slope and
replacing with suitable native species.
Stabilisation of the slope is urgently required.
Removal of all Feral Cats from the area.
7.4.10 LITTLE BAY:
Requires the removal of all refuse and debris found within the vegetation.
Removal of all Feral Cats from the area.
7.4.11 ROSIA:
The future development and use of Rosia Bay is still uncertain. When proposals for this area are submitted,
an environmental impact assessment should take into consideration the cliff habitat and also provide
green areas in this otherwise mostly concreted zone.
7.4.12 SOUTH DISTRICT OVERALL
The South District, as defined above, would greatly benefit from having an overall plan allocating future
projects in the whole of the area in an environmentally sensitive way, rather than in the haphazard way that
they are being developed. This could easily be produced by a small, multi-disciplinary team,

8. URBAN GREEN AREAS
Figure 12: Westview Park, a good example of landscape architecture
incorporating some native species.
Until the early 1990s, green areas in urban zones were given little importance by the authorities and it
was only as a result of the improvements in the Costa del Sol, and in particular Marbella, that the
Government worked at improving the appearance of built-up Gibraltar. A firm of horticultural contractors
was engaged to improve the appearance of planted areas in Gibraltar, and in particular the entrance into
the town area from the frontier.
Urban Green Areas consist mainly of gardens, roadside verges, avenues and planted areas within the
town area and suburbs. As well as the Alameda Botanic Gardens, the most significant are the large gardens
of the Mount, the Convent, Rock Cottage, Engineer House and Westview Park. Smaller garden areas
are scattered around the town area and include the Garrison Library, Bristol Hotel and Europort Gardens,
but the majority of small gardens and urban green areas are in the South District.
The Alameda Botanic Gardens, inaugurated in 1816 by the then Lieutenant-Governor of Gibraltar,
George Don, houses a range of exotic plants from around the world, but also contains a variety of native
species. The Gardens have progressed from being an ordinary park to a botanic garden whose aim is to
promote and enhance its collection through the creation of thematic beds, including the Mediterranean bed
with many of Gibraltar’s interesting native plants. It also contains an important seed bank of local species,
and aims to create public awareness of our rich botanical heritage through the creation of an interpretation
centre, and its frequent guided walks and literature.
The Mount gardens contain a locally unique collection of ancient native trees, many of them remnants
of Gibraltar’s original vegetation. These include Algerian Oak Quercus canariensis, Bay Laurel Laurus
nobilis, and Nettle Trees Celtis australis (probably a long-established introduction), but also some exotic
species including Magnolias Magnolia grandiflora, Indian Laurel Ficus microcarpa, Atlantic Cedar Cedrus
atlantica, Dragon Trees Dracaena draco and many shrubs.
The Convent Gardens also house a wonderful collection of mature exotic trees including Araucaria bildwildii,
Norfolk Island Pine Araucaria heterophylla, some very old Dragon trees Dracaena draco, several
Palm trees Phoenix sp. and other exotic and native trees and shrubs. It also contains possibly the oldest
Carob tree Ceratonia siliqua in Gibraltar, many of its branches held up on supports.
The Trafalgar Cemetery also contains many mature trees and several old Dragon trees are also located
in the Garrison Library gardens. All these gardens include, among their exotic species, important collections
of Gibraltar’s natural botanical heritage.
The rest of the smaller gardens in Gibraltar, such as Westview Park and those found in the South
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District, contain mainly younger trees, including Olive Olea europea and other native species but also many
exotic species of herbaceous plants and shrubs. These small pockets of vegetation are important refuges
for wildlife including birds, reptiles and invertebrates and provide links with other habitat areas.
Roadside verges, tree avenues and estate boundaries are usually planted with exotic species, adding
colour and greenery throughout the year. Prime examples are the vegetated entrance into the town area
from the frontier and Rosia promenade. They are appealing to the public and also to wildlife, with exotic
flowers providing nectar for insects and branches providing perching and nesting places for birds and invertebrates.
Urban green areas as a whole provide a habitat for other wildlife, being important, if not treated with
chemicals, as foraging areas for House Sparrows Passer domesticus, and also used by Blackbirds Turdus
merula, Sardinian Warblers Sylvia melanocephala and Blue Tits Cyanistes cyaneus for nesting and feeding,
and by species such as Robins Erithacus rubecula, Black Redstarts Phoenicurus ochruros, Blackcaps
Sylvia atricapilla and Chiffchaffs Phylloscopus collybita in winter.
8.1 Current Status
8.1.1 LEGAL STATUS
The major gardens in Gibraltar do not have any legal protection, although they should for their historical
and natural heritage value.
A Tree Preservation policy was initiated by GONHS and adopted by the Development and Planning
Commission, aimed at protecting Gibraltar’s trees, and these include many within and some outside the
gardens themselves.
8.1.2 MANAGEMENT, RESEARCH AND GUIDANCE
The Tree Preservation Policy was prepared in 2002 and adopted by the Development and Planning
Commission. Based on a system of assessments of tree values used both in the United Kingdom and the
United States, the principle adopted was one that trees in Gibraltar had to be protected and managed sensitively.
One of its main aims was to ensure the protection of Gibraltar’s oldest and rarest trees. Trees (and
green areas) were mapped and categorised and incorporated into the Gibraltar Government’s GIS mapping
scheme that will facilitate the assessment of new developments on the Rock. The Policy states that
any tree whose removal is inevitable (such as for safety reasons) needs to be replaced, and builds on the
procedure to issue Tree Preservation Orders by introducing a formal procedure. This however needs to be
established firmly by legislation.
The Alameda Botanic Garden continues its efforts to conserve Gibraltar’s rare plants through planting
and re-introduction schemes. The garden also maintains and continues to improve its native plant seed
bank.
8.2 Current Factors affecting Habitat
Several factors are adversely affecting green areas:
• Unnecessary, often annual pruning by Horticultural Contractors.
• Over-zealous, unsustainable pruning and topping of trees, leaving them unable to recover, and even
causing disease and death.
• Pruning at wrong times of year during drought conditions.
• Illegal pruning/poisoning of trees that block views or shop-fronts by the public and shop-owners. Such
incidents are currently not investigated or prosecuted.
• Little or no consultation when removing trees or clearing green areas.
• Insufficient consultation on species selection for planting leading to the threat of alien invasives being
introduced.
• Use of pesticides and herbicides in green areas without regard to invertebrates in particular.
• Green areas used as dog toilets.
• Unnecessary strimming of ground vegetation in areas such as road verges and Alameda Estate.
• Westview Promenade lawns being used as a sports-ground and as a beach area in summer (although
swimming is prohibited)
8.3 Current Action
There are tentative plans to integrate Engineer House gardens as a garden area within a new proposed

development.
No other actions are taking place currently.
8.4 Threats
Green areas are under threat of being given over to development. An example in question is the
Europort Gardens that has been destroyed to make way for a swimming pool and car-parking facilities,
although with the condition that green areas be re-established.
With exceptions, such as Ocean Village in Marina Bay, Little importance has been given to incorporating
green areas into developments.
Green areas, in beguiling artists’ impressions in development planning proposals, often do not materialise
on completion.
8.5 Conservation Direction
The authorities should incorporate landscape architecture within their remit and develop a Gibraltar
landscape plan. This would not only beautify Gibraltar but would also benefit biodiversity and provide an
inspiring living environment, which would contribute to human well-being.
Action should be taken by the Department for Trade and Industry, the Town-Planners Office and the
Ministry for the Environment.
Consultation should take place with the GONHS, Heritage and Planning Division, the Heritage Trust and
the Gibraltar Museum.
Action required:
• Incorporation of landscape architecture within proposed and existing developments.
• Development of an environmental strategy for green areas.
• Establishment of a Tree Preservation Ordinance based on the Tree Policy and incorporating the procedure
for issuing Tree Preservation Orders.
• Establishment of legal protection and conservation measures for major gardens.
• Formalisation of consultation processes within Government Departments, NGO’s and other bodies.
• Representation of native species within planted zones.
• Establishment of a code of practice for the Horticultural Contractors.
• Strict control of the use of pesticides and herbicides
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9. URBAN AREAS
Figure 13: A view of the Town of Gibraltar.
The inclusion of Urban areas within ‘habitats’ may come as a surprise, but the buildings and structures
of towns and cities are attractive to a wide range of wildlife. For example, buildings are substitutes for cliff
habitat for many species of birds that use the convenient recesses and eaves found in buildings and roofs
as nesting sites. These recesses are warm during the winter months, providing important roosting sites for
bats.
Storage facilities, water tanks and underground structures, including sewers, provide refuges and
breeding sites for a broad range of wild species that have over the years adapted to living in these artificial
conditions and are now more commonly found in urban areas than in the wild.
Human activity also inadvertently and unintentionally provides a food source for wildlife, in the form of
food storage facilities, discarded refuse or the active feeding of birds.
The most common vertebrate species of wildlife found in the Urban habitat are given in Table 10:
Table 10: Common Urban wildlife.
Common Name Scientific name
Feral cat Felis catus
Feral Pigeon Columba livia
European Free-tailed Bat Tadarida teniotis
Soprano Pipistrelle Pipistrellus pygmaeus
Black Rat Rattus rattus alexandrinus
Brown Rat Rattus norvegicus
House Mouse Mus domesticus
Kestrel Falco tinnunculus
House Sparrow Passer domesticus
Blackbird Turdus merula
Common Swift Apus apus
Pallid Swift Apus pallidus
Spotless Starling Sturnus unicolor
Moorish Gecko Tarentola mauretanica
Turkish Gecko Hemidactylus turcicus
Iberian Wall Lizard Podarcis hispanica

Many species (Table 11) have become adapted to living indoors as pests in houses and in food storage
facilities:
Table 11: Invertebrate groups found commonly indoors.
Order Family Common Name
Thysanura Lepismatidae Silverfish, Firebrats
Thripidae Thrips
Collembola Springtails
Dermaptera Forficulidae Earwigs
Neuroptera Chrysopidae Lacewings
Orthoptera Gryllidae Crickets
Isopoda Oniscus Woodlice
Myriapoda Chilopda Centipedes
Diplopda Millipedes
Dictyoptera Blattidae Cockroaches
Pscoptera Booklice
Coleoptera Dermestidae Hide & Leather Beetles
Anobidae Biscuit/Cigarette Beetles
Ptinidae Spider Beetles
Carabidae Ground Beetles
Staphylinidae Rove Beetles
Bostrychidae Wood/Grain Borers
Cleridae Chequered Beetles
Cucujidae Bark/Grain Beetles
Silvanidae Flat Grain Beetles
Tenebrionidae Flour Beetles
Bruchidae Seed Beetles
Anthribidae Fungus Weevils
Curculionidae Weevils
Nitidulidae Sap/Fruit Beetles
Lathridiidae Plaster Beetles
Cryptophacidae Mould Beetles
Mycetophagidae Fungus Beetles
Diptera Culicidae Mosquitoes
Drosophilidae Fruit Flies
Muscidae House Flies
Calliphoridae Blow, Flesh Flies
Psychoididae Drain/Filter Flies
Lepidoptera Tineidae Clothes Moths
Oecophoridae House Moths
Pyralidae Dried Fruit Moths
Hymenoptera Formicidae Ants
Vespidae Wasps
Acaridae Mites
(National Britannia Ltd, 1998)
Many plants have also found a refuge in fissures and recesses in the old city walls and on some of the
older buildings in the Upper Town. In most cases they do not harm the structure of the walls, as their root
systems are incapable of penetrating and enlarging the fissures. They provide colour and an aesthetic
value to the character of the upper town. Nevertheless there are some species that can do serious damage
if they are permitted to grow unchecked. The most serious is the Fig Tree Ficus carica and other, introduced
Ficus species that can be seen growing on occasions on the City Walls.
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Table 12: Main urban species of flora.
Achyranthes sicula Lactuca tenerrima
Amaranthus blitoides Lamarckia aurea
Amaranthus lividus Lavatera cretica
Anacyclus radiatus Linaria tristis
Anogramma leptophylla Lobularia maritima
Antirrhinum majus ssp. cirrhigerum Lotus collinus
Antirrhinum majus ssp. tortuosum Malva sylvestris
Asplenium ceterach Medicago lupulina
Asplenium trichomanes ssp. quadrivalens Medicago polymorpha ssp. polymorpha
Asteriscus maritimus Melilotus indica
Bidens pilosa Mercurialis annua ssp. ambigua
Biscutella megacarpaea Nicotiana glauca
Borago officinalis Oxalis articulata
Campanula erinus Oxalis corniculata
Campanula velutina Oxalis pes-caprae
Cardamine hirsuta Parietaria judaica
Carduus pycnocephalus Parietaria lusitanica
Carduus tenuiflorus Parietaria mauritanica
Centranthus ruber ssp. ruber Phagnalon saxatile
Centranthus calcitrapae Phytolacca americana
Chenopodium album ssp. album Picris echioides
Chenopodium ambrosioides Piptatherum miliaceum
Chenopodium murale Poa infirma
Coronopus didymus Polycarpon tetraphyllum
Cymbalaria muralis ssp. muralis Sagina apetala ssp. apetala
Cyperus rotundus Sedum album
Dittrichia viscosa ssp. viscosa Senecio vulgaris
Erigeron bonariensis Sisymbrium irio
Erigeron sumatrensis Sisymbrium officinale
Erodium chium ssp. chium Solanum nigrum ssp. nigrum
Erodium moschatum Solanum villosum
Eucalyptus camaldulensis Sonchus oleraceus
Eupatorium rugosum Sonchus tenerrimus
Euphorbia helioscopia Spergularia marina
Euphorbia peplus Stellaria pallida
Ficus carica Symphyotrichuym squamatum
Freesia refracta Torilis arvensis ssp. neglecta
Fumaria capreolata ssp. capreolata Trachelium caeruleum ssp. caeruleum
Galium murale Umbilicus horizontalis
Geranium purpureum Umbilicus rupestris
Glebionis coronaria Urtica membranacea
Helichrysum rupestre Verbena officinalis
Heliotropium europaeum Veronica cymbalaria
Hyoscyamus albus

9.1 Current Status
9.1.1 LEGAL STATUS
Urban areas do not have any legal conservation protection measures, other than that afforded to individual
species by the Nature Protection Ordinance. Nevertheless there are historic buildings within those
areas that do have protection for their historic value and are considered listed buildings. The list of such
buildings is currently being assessed by the Gibraltar Heritage Trust and the Gibraltar Government with the
collaboration of the Heritage and Planning Division.
9.1.2 MANAGEMENT, RESEARCH AND GUIDANCE
Many of the older buildings in the town area were constructed in a way that inadvertently provided cavities
and recesses for the large population of Common and Pallid Swifts. Most were bestowed with tiled,
pitched roofs with space under the eaves that were ideal resting and nesting places for the birdlife and for
bats. Since then, building practices have changed and new roofs tend to be flat, with few cavities available.
The loss of many old buildings with their large colonies of swifts impelled GONHS to publish a leaflet to
guide developers in providing cavities in roofs and incorporating bat and swift boxes within new developments.
That publication, ‘Bats and Swifts in Buildings’ (Santana & Cortes, 1996), made several observations
and recommendations including:
• Bats and swifts are a natural insect control.
• Roofs are used as roosts and nurseries by bats.
• Demolition and remedial works should be timed to avoid the breeding season.
• A licence under the Nature Protection Ordinance is necessary when works are unavoidable.
• Alterations to roofs should accommodate use by bats.
• New roofs and buildings should provide nesting sites for swifts.
• Artificial nests should be incorporated in new and existing buildings.
In 2004, many artificial nests were incorporated on to the buildings around Varyl Begg Estate. It is gratifying
to see that the Development and Planning Commission is implementing some of these recommendations,
and all new developments should also follow this initiative.
The development of new constructions with flat roofs in Gibraltar should incorporate the new building
concept of green roofs. Both pitched and flat roofs can be provided with a green cover. The benefits are
great, not least to biodiversity and the environment. They also provide other benefits to the building itself.
• Due to the high degree of insulation that they provide, green roofs are known for their ability to stabilise
temperature throughout the year. During the winter they keep the heat in and in the summer they
provide a relatively cool environment.
• Green roofs also have the ability to soften harsh edges of buildings in sensitive environments, making
them blend in with the surrounding area.
• Turf and green roofs provide an ideal habitat for non-pest insects and other wildlife.
• They replace the habitat that has already been lost in green zones.
9.2 CURRENT FACTORS AFFECTING HABITAT
The urban habitat is rapidly expanding and encroaching on green habitats.
The Gibraltar Development Plan 1991 is outdated and obsolete. Indeed, until recently there has been
no attempt to devise an urban strategy for Gibraltar, which would incorporate building developments within
the overall habitat structure of Gibraltar. An example of the lack of coordination between projects is seen
in the proposals for developing the Lathbury Barracks area, where it was decided to establish an industrial
park. At the same time, a new prison is to be located there. There are also plans for a relocated Power
Station and a seven storey luxury housing unit in the most exposed location of this area, partially obstructing
the view of the Strait from the prime tourist viewing point at Jews’ Gate.
Representations are made to the Development and Planning Commission by the NGO’s represented
there (GONHS and the Gibraltar Heritage Trust) when proposals affect heritage and/or the environment.
The Commission’s decisions need to be backed by hard facts and current development strategies, which
takes account of environmental concerns including those enshrined in the Environment Chartered adopted
by the Government in spring 2006. This inevitably requires that a new development plan, the drafting of
which began in 2004, be finalised as soon as possible.
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9.3 Current Action
None.
9.4 Conservation Direction
A new Gibraltar Development Plan is urgently required to set out an overall development strategy for
Gibraltar that will incorporate the needs of the natural environment.
The new Gibraltar Development Plan should incorporate adequate strategies for environmentally friendly
building practices within developments. These should include:
• Energy-efficient building designs.
• Solar panels and wind turbines.
• Environmentally engineered structural insulating panels.
• Bioshield paints that contain virtually no toxic, volatile, organic compounds.
• Eco-friendly, recycled building materials such as tiles, flooring, glass, etc.
• Recycled plastic lumber for exteriors (as recommended for the Nature Reserve fencing by Perez &
Bensusan 2005).
These and other environmentally friendly building practices could form part of a ‘Green Building
Ordinance’, a document that is commonly utilised by many municipalities worldwide, which would set out
the requirements of green building practices and future building construction. Such practices would primarily
address water management, reduction of energy consumption, the use of sustainable and recyclable
building materials and the provision of green areas, roofs and terraces.
Further Reading:
• Sustainable Building Task Force and the State and Consumer Services Agency. (2001) Building
Better Buildings. A Blueprint for Better Sustainable Facilities. The State of California.
• City of Oakland Public Works Agency. Green Building requirements for city building projects and
traditional public works projects. www.oaklandpw.com
• US Department of Energy. Green Building Guidelines. Meeting the Demand for Low-energy
Resource-efficient Homes. Fourth Edition. Building America. The Sustainable Buildings Industry
Council.
• Kats, G., et al. (2003) The Costs and Financial Benefits of Green Buildings. The Sustainable Building
Task Force. The State of California.
• Kidd, J., Optimum Green Roofs for Brisbane. Student Thesis. Abstract in www.greenroofs.com. The
LEED (Leadership in Energy and Environmental Design) Green Building Rating System ®
www.usgbc.org

10. CAVES
Figure 14: Lower St. Michael’s Cave (T. Berge).
The limestone Rock of Gibraltar has a wealth of natural caves, with over 143 recorded by George Palao
in the 1960s and 70s (Palao, Unpubl). Many other caves that were formed during periods of glaciation can
now be found below the present sea-level. Some caves were formed by the action of rainwater eroding
cavities or shaping faults, (e.g. the St. Michael’s caves series, while others were largely formed by the
action of the sea. Examples of sea caves can be found at Governor’s Beach, which is lined with several,
among them Gorham’s Cave which has rich archaeological deposits. Even caves high up on the Rock, like
Martin’s Cave and Goat’s Hair Twin Caves, are examples of sea caves originally formed at sea level.
Another particular area of Gibraltar, North Gorge, is geologically significant because it is riddled with faults
and fissures that can be identified with ‘karst’ scenery. Situated between the limestone plateaus of Windmill
Hill and Buena Vista, this area contains important caves like Judge’s, Glen Rocky Shelter, Horseshoe and
Glen Rocky Cave amongst others. Many of these contain important archaeological deposits while others
have held important colonies of bats.
Caves, by their nature, have a stable environment buffered against the daily, seasonal and longer-term
surface climatic conditions. They provide a stable, sheltered, moist refuge for animals that would not otherwise
survive on the surface. Green plants do not survive in the complete darkness of caves so the food
supply for cave creatures must ultimately come from the surface. This is usually in the form of plant material
that is swept in by rainwater through cracks and fissures, roots that penetrate deep into the ground in
fissures, or animals that fall or are swept underground and are unable to find their way out. The cave
ecosystem depends entirely on the surrounding surface environment. The vegetation, nature of the soil
and water quality and availability is crucial to this ecosystem, and therefore karst areas are particularly vulnerable
and should be treated with special care to ensure the survival of cave ecology.
Many caves in Gibraltar contained colonies of Schreiber’s and Mouse-eared Bats that numbered in the
thousands (Palao Unpubl.), but in recent years there has been a marked decline with only a few hundred
Schreiber’s Bats remaining in Martin’s Cave in the late 1980s. Since then this colony has also been lost
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despite the best efforts to minimise disturbance by the erection of grilles and fences to prevent access.
Prospecting bats may eventually recolonise some of the caves if proposed cave management and conservation
measures are enforced (Perez & Bensusan, 2005).
Cave entrances are also a refuge for many animals and plants for they provide a stable atmosphere
where the wildlife can find moisture even in the height of the summer months. Mosses, algae, fungi and
several higher plant species find the walls and deeper recesses of the cave walls, where daylight penetrates
the darkness, to their liking. In the summer months a fly species (Diptera) aestivates on the cave
walls in its millions, which may provide a source of nutrients to bats within the caves and in the immediate
area. Holes and ledges in roofs of the cave entrances provide nesting places for Pallid and Alpine Swifts,
Spotless Starlings, Wrens and warm and sheltered roosting places for hundreds of Crag Martins in the winter
months. Ledges in the caves at Governor’s beach are used as nest sites by Western Mediterranean
Shags.
10.1 Current Status
Many of the accessible caves in Gibraltar are in a dilapidated state. Those along the Mediterranean
Steps are strewn with litter and many cave walls are covered with graffiti. Martin’s Cave, the last cave to
hold a colony of bats, was until recently protected with fencing and a grille to prevent access, however, this
has been vandalised and removed.
Bray’s Cave, a rock shelter on the Upper Rock Nature Reserve, was the site of an archaeological dig
in 2002. The site now remains in an abandoned state with large pits and a grid of wires that constitutes a
safety hazard and is a danger to the public. The dig material has been deposited on several levels outside
the cave.
The Governor’s Beach series of caves was most likely compromised by the extraction of sand offshore
for the Europort reclamation project. The beach was subsequently lost as a result and the waves now
break very close to several of the cave entrances and wash the cave deposits away. Gorham’s Cave was
also the site of an ongoing archaeological dig and much of the infrastructure and grid of wires are also in
place and constitute a hazard for wintering Crag Martins and other wildlife, including possibly bats.
Old St. Michael’s Cave, one of the main tourist sites on the Upper Rock Nature Reserve, is in a poor
state. Most of the formations are now dead (i.e. dry without any further accumulation of calcium carbonate
being deposited by rainwater filtrations), and covered in a coating of dirt. Visitor numbers are not restricted
and this is further aggravating the natural state of this cave. This cave contained a particular species of
woodlouse Iberoniscus beruili, a cavernicolous species that was collected in 1950 under rotten wood deep
in the cave (Easter, 2005). Most of the cave was covered in concrete and converted into an auditorium,
but there remain many areas where the species may have survived.
Poca Roca Cave, situated within the residential complex of the same name within the Upper Rock
Nature Reserve, lies directly behind one of the houses. The cave, which held important archaeological
artefacts, was fitted up as the residence of the Governor in 1789, but never used (Palao, 1969).
The Tourist Board manages new St. Michael’s Cave, which contains a small freshwater lake. Visits are
controlled, and guided by experienced personnel. This cave is being used for a scientific project to assess
climate change patterns, in a collaborative programme between the Royal Holloway College of London
University and GONHS.
There are many caves and fissures in the North Gorge area, amongst which Glen Rocky, Glen Rocky
Shelter and Judge’s Cave are the largest. Judges Cave entrance was buried under piles of rubble inbetween
the foundations of the old Workers Hostel, and was recently uncovered by members of the
GONHS Caves and Cliffs section. Glen Rocky Shelter Cave lies at the base of the western cliff of the
Gorge. It was used as a bomb shelter during WWII, and has been used by bats in the past (Palao, Unpubl).
The North Gorge area is heavily faulted with many deep fissures running North West-South East, joining
up with Devils Falls Cave in Camp Bay, running under the Buena Vista plateau. This area is a prime example
of the karst scenery, with limestone pavements, fissures and gorges with sinkholes, which require conservation
and protection.
Ragged Staff Cave, located deep in Ragged Staff tunnel, lies below the Alameda Grand Parade car
park. It is a unique, large cave, containing a small lake where the fresh upper layers merge with the lower,
salt-laden ones. Members of the Gibraltar Museum have discovered a small, unidentified crustacean in the
lake, and this species will probably be new to science (D. Fa, pers. comm.). Other discoveries may yet

await discovery within the depths of this cave.
10.2 Current Factors affecting Habitat
Several factors can and do affect the caves of Gibraltar, although only those that can have an effect on
biodiversity are listed below:
• Accidental and intentional disturbance to bats in caves.
• Deposition of rubbish and use of the cave as a toilet.
• Illegal digging in search for archaeological artefacts.
• Disturbance to cave ecology and wildlife by archaeologists.
• Alterations caused by urban developments.
10.3 Current Action
An assessment together with recommendations for the conservation and management of the caves
within the Upper Rock Nature reserve was prepared in Perez & Bensusan (2005). Action on the recommendations,
including that which calls for the creation of a Cave Management Committee has not yet been
taken.
10.4 Threats
The North Gorge area is earmarked for development. The area has several important caves, with some
of the caverns lying directly below part of the proposed site. The area is also heavily faulted with numerous
fissures running mainly south-west to north-east and south to north. It suggests strong geological tectonic
movements in the past and it is suggested that it is not the ideal location for a residential area, as any
earthquake shocks may be accentuated along this faulted zone. Proposed houses on Buena Vista plateau
may also damage part of the cave systems beneath.
10.5 Conservation Direction
The recommendations published in Perez & Bensusan (2005) should now be implemented. A Cave
Management Committee should be established, under the guidelines stipulated within the report, which
would address the conservation needs of all caves, both from an archaeological and a biological point of
view, harmonising any possible conflict between these. Particular caves that are accessed by the public
(e.g. those along Mediterranean Steps) should have information panels depicting their main historical and
natural aspects and values.
There is a need to establish a research programme to assess the cave ecology and biodiversity value
of all caves in Gibraltar. This would include surveys for bats, invertebrates and other wildlife found all the
way from the entrances right into the depths of the caves.
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Marine Habitats
The marine habitats and marine sites are found within an area around Gibraltar that stretches to three
miles east and south of the Rock and to a median line dividing the territorial waters of Gibraltar and Spain
in the Bay of Gibraltar in accordance with the 1958 Geneva Convention on the ‘Territorial Sea and
Contiguous Zone, between British and Spanish territorial waters’. They also include the intertidal zone, the
coastal area washed by the tides. Amongst the different habitats, sites and benthic types referred to here
are:
• The Intertidal Zone
• The Artificial Reef
• Reefs and inshore rocky outcrops
• Sand
• Marl
• Rock
The distribution of the main benthic types and the inshore rocks and reefs are shown in Figure 15.
Figure 15: Main benthic types found in Gibraltar waters.
The purple areas are inshore rocks and reefs.
In addition Gibraltar’s open waters comprise a pelagic zone that has a constant interchange between
the saltier, denser waters leaving the Mediterranean and the cold surface Atlantic waters that enter eastwards.
The currents and upwellings within the Strait bring nutrients that stimulate the growth of plankton.
Pelagic fish are attracted to feed on the plankton and predatory fish and cetaceans follow these shoals.
Table 14 gives some of the fish found in mid-waters:

Table 13: Main pelagic and predatory fish found in the Strait of Gibraltar.
Common Name Scientific Name
Pompano Trachinotus ovatus
Mediterranean Horse Mackerel Trachurus mediterraneus
Blue Jack Mackerel Trachurus picturatus
Atlantic Horse Mackerel Trachurus trachurus
Picarel Spicara flexuosa
Blotched Picarel Spicara maena
bluefish Pomatomus saltatrix
Atlantic Saury Scomberesox saurus
Bullet Tuna Auxis rochei
Little Tunny Euthynnus alletteratus
Skipjack Tuna Katsuwonus pelamis
Atlantic Bonito Sarda sarda
Chub or Spanish Mackerel Scomber japonicus
Atlantic Mackerel Scomber scombrus
Albacore Thunnus alalunga
Northern Bluefin Tuna Thunnus thynnus
Yellowfin tuna Thunnus albacares
Swordfish Xiphias gladius
The large Bluefin and Yellowfin tuna have migratory populations that breed in the Mediterranean and
pass through the Strait of Gibraltar. Their movements were well known to the Romans who erected inshore
intercept nets in their path to catch them. This method is still used along the Mediterranean, but as catches
have dropped many fisheries have ceased operation. The La Linea net used to catch large quantities
of the large tuna but in the last twenty years only the Bullet Tuna Auxis rochei, known as Melva in Spain,
was being caught in any numbers. The La Linea operation ceased altogether in 1997.
Many large species of predatory fish, mainly of the tuna family, are highly prized as culinary items, especially
by the Japanese. Their fishing fleets have followed Tuna shoals worldwide and have decimated their
numbers. The populations within the Mediterranean have not escaped their wide ‘net’, and most of the tuna
catches, in the remaining traditional pen nets known as ‘Almadrabas’ in the Tarifa and Barbate area, are
sold directly to Japanese fishing boats. They also lay intercept drift nets many kilometres long (which are
outlawed in the European Union) and longlines to catch tuna and in the process also catch and drown numbers
of dolphins, whales and sharks.
In summer 2005, the GONHS observed Japanese fishing vessels unloading tons of tuna, many of them
immature fish, in Gibraltar. The fish were snap-frozen in special, refrigerator containers for transport to the
Spanish port of Algeciras for trans-shipment. Further investigation is required to establish and ensure that
Gibraltar is not being used as a port to by-pass international or European quotas for fresh-caught fish.
Cetaceans are also prominent in the Bay and the Strait (Table 14) and both Common Dolphin Delphinus
delphis and Striped Dolphin Stenella coerulaeoalba have nurseries in these areas (Shaw, 1998). Whales
are also occasionally seen. ‘Cetacean watching’ has developed into a tourist industry in Gibraltar, Tarifa,
and more recently La Linea, with several Dolphin boats operating in these areas (See Cetacean species
action plan).
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Table 14: Main cetacean species found in the Bay and Strait of Gibraltar.
Common Name Scientific Name
Minke Whale Balaenoptera acutorostrata
Fin Whale Balaenoptera polysalus
Humpback Whale Megaptera novaeangliae
Common Dolphin Delphinus dephis
Pilot Whale Globicephala melaena
Risso's Dolphin Grampus griseus
Killer Whale Orcinus orca
Striped Dolphin Stenella coerulaeoalba
Bottle-nosed Dolphin Tursiops truncatus
Sperm Whale Physeter macrocephalus
Cuvier's Beaked Whale Ziphius cavirostris
Unconfirmed sightings of one other marine mammal, the Mediterranean Monk Seal Monachus
monachus, has been reported on a couple of occasions by scuba divers (E. Shaw pers. comm.), and one
spent several days in waters around Gibraltar in August 2006. It is a very rare species, with a global population
of only 200-300 animals. It once occupied a wide geographic area in the Mediterranean and was
also found on some of the Atlantic Islands. It is listed as critically endangered in the World Conservation
Union (IUCN) Red List and is also listed on Appendix I of the Convention on International Trade in
Endangered Species (CITES).
Our marine wildlife includes several turtle species, which are sighted occasionally.
Table 15: Turtle species that pass through the Strait of Gibraltar.
Common Name Scientific Name
Loggerhead Turtle Caretta caretta caretta
Green Sea Turtle Chelonia mydas mydas
Leatherback Turtle Dermochelys coriacea coriacea
Strong currents and upwellings occasionally bring concentrations of baitfish and other marine organisms
into the Strait and Bay. Amongst the most significant are the visible shoals of red Boar fish Capros
asper, (‘Chavitos’) and occasionally Sprat Sprattus sprattus. When a shoal surfaces to escape predatory
fish below it is often preyed upon by dense flocks of Yellow-legged Gulls. At other times the gulls are after
a species of swimming crab that is a much-prized bait for local sports fishermen, who are guided to them
by the Gull flocks. A huge tide of pink krill, a small crustacean, can be seen in the Strait and Bay in early
summer occasionally (pers. obs.), when many are found dead on the tideline.
The Strait is also an important site for migratory seabirds, both on passage and in winter, and a feeding
site for the Balearic Shearwater Puffinus mauretanicus and the Cory’s Shearwater Calonectris
diomedea. Indeed, the Strait of Gibraltar is recognised formally as an Important Bird Area by BirdLife
International (2004).
The main threats affecting the marine habitats and sites are:
• The risk of oil spillage from bunkering operations throughout the Bay, fuel storage and the Spanish oil
refinery and associated industries.
• The risk of pollution from shipping emptying bilge tanks in the Strait area.
• Excessive use of anchorage areas to the east and west of Gibraltar affecting benthic habitats.
• The risk of invasive species being released from ballast water carried from other locations.
• The release of effluents, e.g. sewage, industrial waste and desalination plant water, into harbour
waters.
• The release of untreated effluents at Europa Point sewerage outfall.
• The reclamation of low-lying inshore waters.
• Illegal seine net, gill net and rake fishing by Spanish commercial fishing boats.
• Illegal spear fishing with breathing apparatus.
• Uncontrolled scuba diving.

• Excessive disturbance of cetaceans by Dolphin tour operators, in the absence of guidelines and
regulations.
• The lack of implementation of the Marine laws under the Marine Nature Reserve Regulations (L/N 143
of 1995).
Many of these threats could be addressed immediately by the Ministry for the Environment, which would
make a huge difference to the marine ecosystem within a few years. The Ministry should devise a management
plan for the marine ecosystem. Such a plan should implement the recommendations in this report
and also the Marine Nature Reserve Regulations (L/N 1995/143) with respect to the candidate Marine
Special Area of Conservation (Fig. 16). It should also provide the infrastructure and support for continual
monitoring and research of the marine ecosystem, to fulfil the requirements and objectives of the
Convention on Biological Diversity.
The Helping Hand Charity, one of the environmental charities associated to GONHS, and with the support
of GONHS, carries out monitoring in the Bay, particularly of cetaceans (e.g. Shaw, 1998).
Figure 16: Gibraltar and its territorial waters and in dark blue the candidate
Marine Special Area of Conservation proposed under the Habitats Directive.
The following habitat and site action plans are far from complete, as only partial information on their status
is available. Work has begun, as part of the Gibraltar Biodiversity Project, to record the species in each
habitat and site and provide a complete picture of the biodiversity in each area.
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11. INTERTIDAL ZONE
Figure 17: A section of the Intertidal Zone at Blackstrap Cove.
The Intertidal or Littoral zone is the area between the high and low water sea-level marks and incorporates
the splash zone. In Gibraltar and the Mediterranean, the intertidal zone is relatively narrow since the
tidal range even during spring tides rarely exceeds 1m, and the average vertical tidal range is usually
between 0.8 – 0.9m. When considering the slight gradient of the shoreline, especially on beaches, the distance
between high and low water mark is approximately 3 - 4m.
The narrow strip of intertidal habitat at Gibraltar is nonetheless extremely important for a wide variety of
marine organisms. It includes the vertical harbour walls, rocky shoreline and sandy or pebble beaches,
each containing its variety of marine life. Of these, the rocky shoreline is by far the richest in biodiversity
although there are interesting species in other intertidal biotopes that also merit conservation. Only 60%
of our littoral zone remains in a natural state. The rest is comprised of the Harbour and Port area, Marinas,
the Airport and reclamation areas.
11.1 Current Status
11.1.1 LEGAL STATUS
The marine area between the south side of Sandy Bay, around Europa Point and north to the southern
end of the South Mole is a candidate Special Area of Conservation (cSAC) under the Habitats Directive
92/43 EEC. This obviously includes the intertidal zone and incorporates one of the best natural coastlines
of this habitat in Gibraltar.
Two mollusc species that are classified under Annex IV of the Habitats Directive 92/43 EEC under
‘Animals and Plant Species of Community Interest in need of strict Protection’ are found in this habitat.
They are the Mediterranean Ribbed Limpet Patella ferruginea and the Date Mussel Lithophaga lithophaga.
11.1.2 MANAGEMENT, RESEARCH AND GUIDANCE
Some research carried out on the intertidal zone has produced considerable information on the marine
communities. The species found include three that are included in the list of Threatened or Endangered

Species of Annex II of the SPAMI Protocol. They are
• Mediterranean Ribbed Limpet Patella ferruginea
• Black Limpet Patella nigra
• Mediterranean Seaweed Cystoseria mediterranea
Several research theses and dissertations have been carried out on different aspects of the Intertidal
zone in Gibraltar. Ocaña (1997) studied the limpet Siphonaria pectinata. Others have researched the
communities of marine life in the intertidal zone (J. Fa, 1990; D. Fa, 1998) and one particular study looked
into the impact of the waste water effluents at Europa Point (Warr, 2004).
11.2 CURRENT FACTORS AFFECTING HABITAT
Much of the intertidal zone has undergone drastic change in the past and continues to change as new
reclamation projects and other developments emerge. Much of the natural Intertidal zone has been
replaced by an artificial one of a substantially different character. Whereas natural intertidal zones often
sloped into shallow waters, the boundaries of the artificial zones have been extended into deeper waters.
The structure of the artificial boundary and the angle of its slope greatly influence the size and species composition
of this habitat. Exposure to greater wave action will also influence species selection as the larger
waves allow certain species to live higher in the inter-tidal zone and select for those that will resist the
strong forces without being washed off the rocks. These factors have to be considered when establishing
artificial littoral boundaries.
The Intertidal zone and marine life inside the harbour was greatly compromised by the reclamation,
which sealed the channel under the viaduct bridge that used to allow an ample exchange of the harbour
waters with those of the Bay. The present currents are sometimes insufficient to allow floating debris to
escape via the harbour entrances, and this indicates that the same holds true for the exchange of waters
during the tides. The low tidal range would mean that at certain times of the year there is a degree of stagnation
of the harbour waters that is likely to affect marine life within this area.
The harbour waters are also affected by effluents from the desalination plant, increasing the salinity and
temperature in a corner of the harbour with low water exchange. Other effluents from industry, marinas and
residential areas surrounding the harbour, and the occasional oil pollution incidents, combine to seriously
decrease the biodiversity of the harbour area.
Sewage effluent at Europa Point can be detrimental since it not only contains domestic waste matter
but also that from industrial establishments. Nevertheless sewage contains nitrogenous waste-based compounds
that in dilution can improve the nutrient content of the waters, stimulating plant plankton growth. It
can also hinder the development of marine organisms when the concentrations are excessive, but this does
not seem to occur at Europa Point where the strong currents ensure that the effluent is quickly dispersed
into the Strait. The shoreline receives a minimal quantity of nutrients in the immediate vicinity of the outfall,
and tests carried out by the Environmental Agency on the water quality of our beaches show that the
water quality complies with European guidelines (EU, 2004), and show that the Europa sewage outfall does
not adversely affect our coastline. The use of salt water in our flushing and sewage systems already
reduces the bacteriological content and activity of the effluent and is in effect already treating the sewage.
The pumping stations, which ensure that gravity carries the effluent to the outfall, significantly reduce the
solid waste to a mainly liquid form. However, the need to comply with European legislation makes it highly
likely that a sewage treatment plant will be installed, as indeed the Government intends to do. Sewage
treatment could have the effect of reducing the food available to the fish that feed near the site, particularly
Thick-lipped Grey Mullet Chelon labrosus.
The Strait of Gibraltar is one of the most congested waterways in the world. On occasion unscrupulous
captains empty their ships’ bilges in this area, discharging quantities of oil into the sea that gets washed up
on the shoreline, with the resulting adverse effects on marine organisms.
11.3 Current Action
None.
11.4 Conservation Direction
Further study of this habitat is required to assess and catalogue all the marine organisms found along
the intertidal zone. An analysis of the geological composition, climatic and geographical factors of the intertidal
zone in relation with species composition will provide an insight into the requirements of specific organisms
and marine communities. This complete picture will enable a comprehensive report on the
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Biodiversity requirements of the habitat in question. It is therefore advisable that there should be a research
and monitoring programme of all marine habitats including the intertidal zone.
However, conservation action should not await the results of such monitoring, and great care needs to
be taken when planning any activity or project that may impact on this habitat, in particular loss due to reclamation.
Careful study to either prevent such activity or to propose actions to compensate or mitigate their
effects must occur on each occasion.
Further Reading:
• Wrigley, S., Wood, B., Wicks, L., Whiting, H., Wood, D., Willock, D., Wilson, N., Warrick, L., &
Wills, A. Sewerage Discharge in Estuaries. A Case for trapping.
• Landeck Miller, R., and Fitzpatrick, J., Water Quality Modelling in New York/New Jersey Harbor: A
Historical Perspective on the Present.
• European Commission (1999). Protocol Concerning Specially Protected Areas and Biological
Diversity in the Mediterranean. Official Journal of the European Communities L322.
Luxembourg.

12. ARTIFICIAL REEFS
Work on the construction of an artificial reef in Gibraltar commenced just off Camp Bay and Rosia Bay
in the winter of 1975 with a small scale attempt at establishing a permanent structure using old car tyres
weighed down with large stones. A second phase in the late 1970s involved the use of car chassis,
arranged three across and two deep, secured with chain and shackles. These structures lasted a limited
time with winter storms stripping and dispersing much of the material and corrosion decomposing the cars.
The third phase of the project in 1983, ongoing still, involved the use of more solid structures: ten sunken
barges covering an overall area of 4,799m 2 (Shaw 1996).
Since then several more vessels of larger tonnage have been sunk in the area adding to the artificial
reefs’ extension.
Figure 18: A Port Department vessel contributing to the Artificial Reef (E. Shaw).
Shaw (1996) noticed a dramatic increase in biodiversity of midwater and bottom-dwelling species,
including sessile organisms on the barges themselves. Marine life had increased from 12 vertebrates and
22 invertebrates previously recorded in the vicinity to 54 vertebrates and 55 invertebrates once the artificial
reef was in place.
12.1 Current Status
12.1.1 LEGAL STATUS
The Artificial Reef forms part of the area that is included as a candidate Marine Special Area of
Conservation (cSAC) under the Habitats Directive 92/43 EEC. It has become the focus for the diving clubs
and diving enterprises in the region, attracting enthusiasts from as far as Rota and Marbella in Spain and
also from the United Kingdom. The rich marine biodiversity that the area has to offer has no equal in the
region and has created a huge interest that is reflected in several articles in diving magazines.
12.1.2 MANAGEMENT, RESEARCH AND GUIDANCE
Monitoring of the species that colonised the Artificial Reef was carried out by the Marine section of
GONHS (Shaw 1996).
Further biological monitoring of the site is an ongoing requirement.
12.2 Current Factors affecting Habitat
Incursions by Spanish seine-net fishing boats close to the area have affected and are affecting the wellbeing
of the biodiversity of this habitat. The remains of some fishing nets have been found snagged onto
the reef, and have had to be removed manually by divers to prevent the accidental catch of fish.
There is absolutely no control on diving at this site. The expertise and standards of diving clubs and
companies and the number of divers that operate on this site remains unchecked. This may lead to undue
disturbance to the habitat.
Strict laws regulating the marine environment were due to come into effect on the 1 st January 1996
under the ‘Marine Nature Reserve Regulations’ (L/N 1995/143), but since the marine reserve was never
formally designated these laws have never been applied.
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12.3 Current Action
The Marine Section of GONHS, under Eric Shaw, who is also responsible for the Helping Hand Charity,
continues to lobby for the disposal of old vessels to be incorporated within the Artificial Reef.
12.4 Conservation Direction
Laws dealing with the illegal fishing with nets by Spanish fishing boats should be enforced.
Annual and seasonal surveys of the biodiversity of the Artificial Reef and other research projects would
provide a clear picture of the marine life of this habitat. This would give an insight into the habitat requirements
of the species in question with a view to improving further the appropriate location and depths for
future vessels to be added to the reef, enhancing the biodiversity of this habitat.
The designation of the Marine Special Area of Conservation should be closely followed by the application
of the ‘Marine Nature Reserve Regulations’ to the designated site.
Further Reading:
• Sheehy, D. J., (1982) Artificial Reefs in Japan. In Murray, J. D. (ed) Mid-Atlantic artificial reef conference,
a collection of abstracts. New Jersey Sea Grant Report, pp.78-82.
• Stone, R. B., (1982) Artificial Reefs: Towards a new era in fisheries enhancement? Mar. Fish Rev., 44:
2-3.
• Unger, I., (1966). Artificial Reefs – A Review. Special Publication No. 4. American Littoral Society.
Highlands, New Jersey.

13. REEFS & INSHORE ROCKY OUTCROPS
Figure 19: The rocky outcrops at Seven Sisters.
Gibraltar is mainly surrounded by sand, but there are many inshore rocks and some shallow reefs
among which are:
• Europa Reef
• Seven Sisters
• Governor’s Beach Reef
• Sandy Bay Reef
• Eastern Beach Reef
The most significant rocky outcrop is the Europa Reef. This lies approximately southwest of Europa
Point and extends from the shoreline to over 300m. The reef is one of a series of limestone beaches;
Windmill Hill Flats and Europa Flats are the two that remain above sea-level as raised beaches, but the
Europa Reef was submerged after the last ice-age. The Reef is fairly shallow: from 2-10m deep, but averaging
about 6m, and is subjected to the strong currents and rip tides that affect the area. Its position at the
entrance to the Bay and the Strait has meant that this area has become a magnet for marine life that converges
on the reef for food and shelter. Europa Reef has therefore long been a popular sport fishing and
scuba diving area.
The area below Napier Battery is another important rocky area for marine species. This is the area
known as Seven Sisters, named after the main rocks that break the surface, and is another important
marine site that harbours interesting marine life, including endemic nudibranchs (Garcia-Gomez 1983,
1987; Garcia-Gomez & Cervera, 1989). The rocks here are composed of breccias, which are softer than
limestone and are similar to those found below Parson’s Lodge Battery. This site is also a well-known
scuba diving and sports fishing area.
The site off Governor’s Beach, a pebble beach, was once a sandy bottom with interspersed rocky outcrops.
In the late 1980’s the area was heavily dredged for a reclamation project. This had a serious effect
on the eastside coastline when, within a few years, the whole of Governor’s Beach material was lost. Other
beaches were also affected but not as seriously as this. The resulting effect was that the inshore sea bottom
around Governor’s Beach became an exposed rocky reef. This site has been colonised by rock-loving
marine species.
Sandy Bay Reef is a small rocky shelf extending out some 60m from the shore and 1-2m deep. Parallel
to the beach a deeper rocky shelf runs 40m out up to the southern end of the beach. This was often buried
with sand but after the dredging that affected the east side it has remained exposed.
The Eastern Beach Reef is a small rocky shelf that lies 50m from the shore between the middle and the
airfield groynes. This reef is frequently exposed after heavy easterlies, which remove the sandy bottom.
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13.1 Current Status
The inshore rocky outcrops and reefs remain virtually unchanged except for the effects of the dredging
in the 1980’s that removed the sand from the eastern side of the Rock, exposing the inshore rocks and
increasing that habitat, as the sandy material gradually filled-in the exposed holes.
13.2 Current Factors affecting Habitat
Several factors are affecting the biodiversity of the habitat adversely:
• Illegal net fishing.
• Excessive long-line fishing.
• Uncontrolled scuba diving.
• Uncontrolled spear-fishing.
• Illegal dumping.
• Illegal fishing by scuba divers.
All of these factors are addressed in the ‘Marine Nature Reserve Regulations’ (L/N 143 of 1995), but
since the marine reserve was never designated these laws have never been applied.
13.3 Current Action
None.
13.4 Conservation Direction
All Marine laws protecting wildlife should be enforced.
Laws dealing with the illegal fishing with nets by Spanish fishing boats should be enforced.
The Police should regularly patrol the Europa Reef, Governor’s Beach Reef, the Artificial Reef and
Seven Sisters where illegal fishing with breathing apparatus, especially for octopus continues unchecked,
despite reports from members of the public.
As with the artificial Reef, similar annual and seasonal surveys of the biodiversity of the Europa Reef
and Seven Sisters would provide a clearer picture of the marine life of these sites. Additionally there is a
need to assess the marine life of the new rocky area of the Governor’s Beach Reef.
The designation of the Marine Special Area of Conservation should be closely followed by the application
of the ‘Marine Nature Reserve Regulations’ to the designated site.

14. SAND
The majority of benthic areas in Gibraltar are composed of sand. This is the most common habitat
found within Gibraltar’s territorial waters, covering most of the eastern and western sides of the Rock.
Nevertheless it is a particularly poor habitat for biodiversity, with few fish species, amongst which the most
characteristic are:
Table 16: Main fish species found over or on sandy benthic habitat.
Common Name Scientific Name
Lesser Weaver Echiichthys vipera
Greater Weaver Trachinus draco
Stargazer Uranoscopus scaber
European Anchovy Engraulis encrasicolus
European Pilchard Sardina pilchardus
Thick-lipped Grey Mullet Chelon labrosus
Bronze Bream Pagellus acarne
Black Bream Spondyliosoma cantharus
Striped Sea-bream Pagellus mormyrus
The east side was also once a rich habitat for a wide variety of molluscs that included the following
species:
Table 17: Main bivalve molluscs that are found in the east side sandy benthic habitat.
Common Name Scientific Name
Chequered Carpet Shell Tapes decussatus
Smooth Clam Callista chione
Pod Razor Shell Ensis siliqua
Wedge Shell Donax trunculus
Corruco (Esp.) Acanthocardia tuberculata
Concha de sangre (Esp.) Glycymeris insubrica
The sandy beaches at Eastern Beach, Catalan Bay and Sandy Bay are frequented by many bathers,
especially in the summer, and are of little ecological interest as a consequence.
14.1 Current Status
The habitat has deteriorated since the 1980s due mainly to excessive rake fishing for molluscs, which
has depleted most of the species that provided the La Linea mollusc fishermen with a living. Tapes decussatus,
a common item in the La Linea fish market in the early 1970s, has practically disappeared.
Acanthocardia tuberculata, once the most common mollusc in the area, which was commonly used as fishing
bait, was also depleted in the 1980s and became scarce. Mollusc fishermen then concentrated on the
Smooth Clam Callista chione, a highly regarded edible species, and by the turn of the century catches of
the species had dropped considerably, and immature specimens made up most of the numbers (pers.
obs.).
The Pod Razor Ensis siliqua survived the onslaught because of its ability to burrow quickly into the
sand, and can still be found in good numbers off Eastern Beach. The Wedge Shell Donax trunculus is
adapted to living close inshore, within 100m, and has survived until now. Nevertheless Spanish fishing
boats continue to fish inside the buoy-demarcated areas of the beaches in the early mornings and indiscriminately
rake for this species. This continues despite the Nature Protection Ordinance, 1991 which prohibits
both the use of rakes in Gibraltar territorial waters. The use of vessels within the demarcated buoyed
areas of the beaches is also forbidden (L/N 143 of 1995).
The loss of the rich mollusc breeding grounds to the east of Gibraltar has had a serious impact on the
quantity and species of fish that frequented these shores. Before the industrialisation of mollusc fishing in
the 1960s, it was commonplace to catch a large variety of fish from the shoreline using beach-casting fishing
methods. Sea Bass and Bream species of considerable size were frequent, but now it is rare to catch
a worthwhile fish of any size (pers. obs.).
Rake fishing in the area of Western Beach and the Airport during the late 1990s destroyed a sensitive
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area of a species of eelgrass that existed in this area (pers. obs.). A subsequent survey of this area to
establish the presence of Posidonia oceanica or other eelgrasses proved fruitless (Fa, 2004). Following
this, part of the site was extensively dredged for another reclamation project.
14.2 Current Factors affecting Habitat
Several adverse factors are still affecting this habitat on the eastern side of the Rock.
• Uncontrolled rake fishing by Spanish boats continues despite Gibraltar laws against this practice.
• Rake fishermen increase the size of the rake’s teeth despite Spanish laws prohibiting this, but since
they fish in Gibraltar waters their authorities are unable/unwilling to enforce this law.
• Despite a Spanish annual close season on mollusc fishing -a ‘parada biológica’ for the species to
recover- Spanish boats continue to fish in Gibraltar waters during this time, knowing full well they can
escape sanction as they are outside the Spanish jurisdiction.
• Net fishing continues around the Rock despite local laws against this practice.
Several proposed reclamation projects may affect the nature of the currents and the deposition of sand
on the coastline. The first, Sovereign Bay, will reclaim a huge area between Eastern Beach and Catalan
Bay, and extend close to 400m out. The second will reclaim an area to the north of the runway that will
seriously affect Western Beach and the waters within the enclosure between the Spanish pier and the
Airfield. Both will require significant environmental impact assessments. The impact of these proposed
projects will need to be monitored as they may not necessarily have a negative effect and may provide additional
littoral habitat, reduce coastal erosion and offer the chance of creating some onshore habitat as well.
14.3 Current Action
None.
14.4 Conservation Direction
The use of offshore sunken breakwaters would benefit sand deposition on our beaches, especially
Sandy Bay. These could be built in the form of concrete modules that interlink to form a formidable offshore
sunken barrier (see figs.19 & 20). These would allow the wave action to transport the sand over the smooth
sloping surface toward the beach but retain it on the steep beach-facing side, thereby depositing sand within
the designated area and preventing loss in heavy levanter conditions. The blocks would need to be located
at a distance beyond that of the major breaking waves during rough conditions to ensure stability, and
would require enough mass and weight to resist the dynamic forces of the wave action. The result would
be two-fold: sand would be deposited between the breakwater and the beach and the force of the waves
would be reduced because they would break further from the shore, reducing coastal erosion.
Figure 20: a. Lateral angled view of breakwater.
b. Lateral view of single block. c. Birds-eye view
of interlocking breakwater blocks.
Figure 21: Lateral view of breakwater.
Sand transported by wave action will be
deposited on the beach side.
These breakwaters would protect the beaches and the intertidal zone from the effects of the strong levanter
waves and currents. They would also create a shallow inshore area that would benefit biodiversity,
in particular fish and molluscs.
Environmental impact assessments are required before the reclamation projects can advance. They
should likewise have been carried out before the accumulation of material for the reclamation project.

15. MARL
Marl is a crumbly composite of clays, calcium and magnesium carbonates, and remnants of shells. In
the sea this benthic habitat forms a hard but muddy bed over intrusions of the shales and mudstones forming
the sea bottom. This is found inshore at only one location: 150m northwest of the North Mole. It is more
common below the 100m mark in the middle of the Bay of Gibraltar and just beyond the three mile limit to
the east of Gibraltar, again at depths of more than 100m.
15.1 Current Status
Status unknown although the area off the North Mole is commonly used as an anchorage for shipping.
It is also a particularly good area for sports fishing, where in particular Bronze bream Pagellus acarne,
Mackerel Trachurus spp. and Sardine Sardina pilchardus shoals congregate in the summer and autumn
months (pers. obs.).
The other known location of this benthic type to the east of the Rock is just outside the limits of Gibraltar
territorial waters and in waters too deep for ships to anchor.
15.2 Current Factors affecting Habitat
The continual anchorage of shipping at the North Mole site would have serious consequences for any
animal life on the sea bottom.
The dredging of the sea bottom close to the site during 2003 and 2004 for aggregate to provide fill for
an extension of existing sporting facilities is likely to have had an impact on this habitat.
15.3 Current Action
There are insufficient data on the composition of the wildlife of this benthic type. Further research is
required to assess the status of this and other marine habitats before a practical habitat action plan can be
implemented.
15.4 Conservation Direction
All the marine and benthic habitat types and sites require further research and investigation to assess
their present status, existing and potential threats fully, and to establish a comprehensive species list for
each habitat. Once this has been achieved then a practical Biodiversity Action Plan of the entire marine
ecosystem may be prepared.
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16. ROCK
Offshore benthic rock habitat is found in deeper waters beyond the benthic sand habitat. Rock is
encountered to the west in the Gibraltar Bay beyond the 100m mark and on the eastern side at a depth
between 50-80m at a distance of 2.5-3km. The eastside site, known colloquially as the ‘three mile reef’ has
been used as a designated anchorage for shipping for over thirty years.
The area off Europa Point beyond Europa Reef is a favourite fishing ground, and a particular site known
as ‘Los Picos’ is a rocky peak 1km out that rises to 20m depth and is exposed to the strong currents in the
Strait.
Other offshore benthic rock bottoms are found beyond the 100m mark where they again give way to
sand.
These two sites off Europa Point were very rich in marine fish species and the European Federation of
Sea Anglers (EFSA) held their championships there in 1969.
16.1 Current Status
The benthic rocky bottoms on the east side are fairly degraded due to excessive commercial fishing and
damage by ship anchors. This has reduced the fish catches at Catalan Bay (C. Riddell pers. comm.).
Rock habitat within the Bay is also quite degraded and is ignored by sport and commercial Spanish fishing
vessels.
The marine area between the south side of Sandy Bay, around Europa Point and north to the southern
end of the South Mole, extending out to three miles of territorial waters and at a mid point in the Bay of
Gibraltar, has been proposed as a candidate Special Area of Conservation (cSAC) under the Habitats
Directive 92/43 EEC (See fig. 15).
16.2 Current Factors affecting Habitat
The recession in shipping from the 1980s onwards has seen usage at the eastside anchorage at an
unprecedented level, as laid-up ships remain for long periods.
The rock habitat off Europa Point has been overfished by Spanish commercial fishing vessels using
multiple hook longlines (in excess of 300 hooks per line), illegal drift and seine nets and illegal spear-fishing
with breathing apparatus. More fish will eventually recolonise the rocks but numbers will not recover
unless over-exploitation ceases.
16.3 Current Action
None.
16.4 Conservation Direction
As with other marine habitats tackled, it is imperative that the relevant Laws of Gibraltar are enforced if
we are to see an improvement and a restoration of the biodiversity in those areas. Amongst the priorities
are:
• Eradication of all commercial fishing in the designated Marine Special Area of Conservation.
• Enforcement of laws on seine and gill nets in Gibraltar Territorial waters.
• Enforcement of laws on underwater fishing with breathing apparatus.
• Establishment of guidelines, regulation and control on sport fishing, spear fishing, and scuba diving
activities in Gibraltar.
• Implementation of a wardening system to oversee the control of the latter.
Other regulations that will be of benefit to the Marine environment and require enforcement can be
found within the Marine Nature Reserve Regulations (L/N 143 of 1995).

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5. Species Action Plans
Species Action Plans have been prepared for the species listed in Table 1. These have been selected
mainly through their negative conservation status in Gibraltar, and also because there are clear steps that
can be taken to protect them and enhance their survival. The list is not exhaustive; that is, non-inclusion
here does not indicate that the species is secure in Gibraltar, nor that no action is needed. Further Species
Action Plans will be prepared, and existing ones reviewed, in the future, in response to changing circumstances.
Action Plans specifically referring to re-introductions and translocation are not included and will form
part of a future publication.
Table 1. Species for which Action Plans have been prepared.
Birds
Western Mediterranean Shag Phalacrocorax aristotelis ssp. desmarestii
Lesser Kestrel Falco naumanni
Peregrine Falco peregrinus
Barbary Partridge Alectoris barbara
Eagle Owl Bubo bubo
Mammals
All Cetaceans
Barbary Macaque Macaca sylvanus
Red Fox Vulpes vulpes silacea
European Rabbit Oryctolagus cuniculus
Soprano Pipistrelle Pipistrellus pygmaeus
Schreiber's Bat Miniopterus schreibersii
Flowering Plants
All Orchids
Gibraltar Chickweed Cerastium gibraltaricum
Gibraltar Campion Silene tomentosa
Gibraltar Thyme Thymus wildenowii
Gibraltar Restharrow Ononis natrix ssp. ramosissima
var. ramosissima
Gibraltar Sea Lavender Limonium emarginatum
Gibraltar Candytuft Iberis gibraltarica
Gibraltar Saxifrage Saxifraga globulifera var. gibraltarica
Bay Tree Laurus nobilis
Narrow-leaved Ash Fraxinus angustifolia
Invertebrates
Insects
Gibraltar Joint-pine Beetle Buprestis sanguinea ssp. calpetana
Arachnids
Gibraltar Funnel-web Spider Macrothele calpeiana
Terrestrial Molluscs
A snail Acicula norrisi
A snail Osteophora calpeana
Marine Mollusc
Mediterranean Ribbed Limpet Patella ferruginea
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Birds:
Class: Aves Order: Pelecaniformes Family: Phalacrocoracidae
MEDITERRANEAN SHAG
Phalacrocorax aristotelis ssp. desmarestii
Figure 1: Mediterranean Shag Phalacrocorax aristotelis desmarestii (Y. Benting)
General Description
This subspecies seems to be double brooded in Gibraltar with nesting taking place in late January and
February (sometimes even late December) and again in late May and June, when after both periods juvenile
birds are frequently seen. The female lays a clutch of 1–6 eggs, although usually 3, nesting on sheltered
cliff ledges often just inside small caves (Snow & Perrins, 1998).
The nominate species is afforded a favourable status in Europe by Birdlife International (2004).
Nevertheless the subspecies desmarestii has a restricted global distribution and is therefore included in
Annex I of the EU Wild Birds Directive, Appendix III of the Bern Convention, and included in the Emerald
Network that aims to establish a network of ‘areas of special conservation interest’. It also has species
action plans under the ORNIS Committee of the European Union and the Standing Committee of the Bern
Convention.
Global Distribution
The nominate subspecies is widely distributed throughout Europe, Asia and Africa but the sub-species
desmarestii, slightly smaller than the nominate race, and whose juveniles are whiter below, is restricted
mainly to the eastern Mediterranean with small populations in the central, western (including the Balearics)
and southern sectors.
Local Distribution
The only recorded breeding site of the Mediterranean subspecies of Shag on the Iberian Peninsula is
Gibraltar. These birds are largely sedentary, so that while the possibility of movements between western
Mediterranean populations does exist, there is nevertheless a possibility of at least slight genetic differences
between them.
The Shag nests on ledges and on the walls of sea caves located north and south of Governor’s beach,

on the east side of the Rock. The population is estimated to be 5–10 pairs but the inaccessibility of the site
and the irregular movements of the species make it impossible to determine precisely. The foraging area
extends from well beyond La Atunara (La Linea, Cádiz) on the Mediterranean side to the northern end of
the Bay of Gibraltar on the west side.
POPULATION TREND: Decreased significantly in the second half of the 20 th Century. Now apparently
stable.
Threat
The Shag is a resilient species that survived the intense disturbance of fast launches, day and night,
during the late 1980’s and 1990s. Nevertheless the species’ breeding success during this period was probably
compromised, as there is evidence of an increase in the population after this period when flocks of up
to a dozen birds were regularly seen (SGBO records). The advent of the noisy jet skis, with their ability to
manoeuvre close inshore is probably the biggest threat to its breeding site. Disturbance at the site by fishing
boats and divers during the breeding season is also a cause of concern.
Furthermore, the area adjacent to the nest site, Governor’s Beach, is frequently used by the MoD to
carry out live firing of guns and controlled pyrotechnic explosions, both land based and just offshore.
The Clay Pigeon Shooting Club has their site in an abandoned state just south of the main nesting area.
The location was once regularly used, utilising lead shot that was fired seawards. The possibility of contamination
to fish and to the marine life in the area, which are part of the food chain of the Shag and other
species of marine wildlife, is worrying. Spent cartridges are also disposed into the sea and cliff area, contaminating
the foraging areas.
The possibility of an oil spill in the area of the Strait of Gibraltar is considerable. Maritime traffic in the
Straits is immense and the waters to the east of the Rock are an official anchorage for large ships and other
vessels. Accidents do occur (although infrequently), but indiscriminate emptying of the ships’ bilges by
unscrupulous captains has produced smaller spills on an annual basis. The Bay of Gibraltar has become
an official bunkering zone, and occasionally accidental spillage of fuel oil does occur. This, and the location
of an Oil Refinery at the head of the Bay, places this zone in serious danger of occasional oil and fuel
spills, and constitutes the largest threat to the survival of this species in the area of Gibraltar.
The feeding area at the northern end of the Bay off the North Mole now sees more maritime traffic than
ever before and this disturbance is worrying. Notwithstanding this there have been improvements to their
feeding grounds off the eastern side where an enterprising Spanish company has set up a mussel rearing
venture with several rafts located a mile offshore. This forms a barrier to motor vessels and unwittingly
provides a resting place and foraging habitat for this species.
The possibility of Shags becoming trapped in tuna fishing nets ceased once the La Linea Almadraba
stopped operating in the 1990s. However, Spanish net fishermen frequently use seine and drift nets within
the Shags’ feeding grounds, sometimes even within the cove which includes Governor’s beach. This
remains another danger to the species.
The population is so small that the loss of very small numbers could have a catastrophic effect and
threaten its survival.
Action
The nesting site of the West Mediterranean Shag needs strict protection. The nomination of a substantial
marine area, which includes the waters around this site, as a candidate Special Area of Conservation
cSAC, will greatly benefit the survival of this species in Gibraltar. If measures are to be taken to ensure the
protection of the species, we must be able to monitor, survey and study this species with a view of improving
and possibly augmenting its nesting possibilities by incorporating artificial nest ledges within the cave.
A reduction of the Yellow-legged Gull population and human disturbance in the area would possibly allow
the expansion of the species to colonise cliff ledges around the site.
Specific action should also include:
• Enforcement of nature conservation laws in respect of net fishing in territorial waters and more specifically
within the areas adjacent to the species’ nesting site.
• Improvement of monitoring of port activities involving fuels.
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Class: Aves Order: Falconiformes Family: Falconidae
LESSER KESTREL
Falco naumanni
Figure 2: Lesser Kestrel Falco naumanni. (P. Acolina).
General Description
The Lesser Kestrel is a small falcon that breeds in colonies in holes in cliffs and buildings. In Gibraltar
it is restricted to a small colony on the North Face of the Rock. Most individuals winter south of the Sahara
and return to their breeding grounds in February and March. The female incubates between four to six
eggs and the chicks are fed mainly on invertebrates and small reptiles that are caught in its favoured foraging
grounds; open habitats.
The Lesser Kestrel is a globally threatened species listed as Vulnerable by Collar et al. (1994). It is
included in Annex I of the EU Wild Birds Directive, Appendix II of the Bern Convention, Appendix II of the
Bonn Convention, Appendix II of CITES and Annex B of the African Convention on the Conservation of
Nature and Natural Resources (Biber, 1990). Locally it is protected under the Nature Protection Ordinance
(L/N 11 of 1991), and its breeding colony falls within the boundary of the Upper Rock Nature Reserve, a
cSAC.
Global Distribution
This species has a Palearctic breeding distribution south of 55°N and mainly winters south of the
Sahara, although some remain in the Mediterranean region (including near Gibraltar) and there are winter
records for Gibraltar up to the 1960s.
Local Distribution
This falcon is restricted as a breeding species to a small colony found on the north face cliffs from below
Princess Caroline’s Battery eastwards. The colony held fourteen breeding pairs in 2005.
POPULATION TREND: Decreasing. It is monitored every year by GONHS.
Threats
The main cause of decline of the Lesser Kestrel is habitat loss and degradation as a result of agricultural
intensification, afforestation and urbanisation. The indiscriminate use of pesticides, including in its
main wintering grounds has also led to a serious decline in the population of the species, with the numbers
of breeding pairs dropping by 95% globally since the 1950s.

In Gibraltar we have also seen a dramatic decrease in the numbers of breeding pairs at the colony, due
to similar reasons (Bensusan & Cortes, in press). The main threat to the Gibraltar colony is urbanisation
and the loss of feeding habitats due mainly to the construction of the airfield and the extension of the town
of La Linea to the north, resulting in the loss of historical feeding habitats. The birds have to make a round
trip of approximately 4 km to bring food back to their chicks. The foraging habitat on the Upper Rock is
unsuitable for these birds that require pastures and agricultural land.
There is also direct competition for nest sites from Feral Pigeons which have been seen to displace
them from nest holes.
Action
Gibraltar authorities can do little about those threats that affect this species which are situated within
Spain. However, they can ensure that all protection and conservation measures that are applicable to
Gibraltar are enforced and adhered to.
Areas of habitat in the isthmus, specifically the aerial farm and the area at the base of the North Face
(see Chapter 4) should be protected and restored to provide some feeding opportunities. Management of
the vegetation of the newly restored habitat on the Great Sand Slopes could also increase the foraging sites
available within Gibraltarian territory. Following this, and as Lesser Kestrels have been bred and reared by
the GONHS Raptor Rehabilitation Unit, it may possible to supplement the colony at North Front with new
individuals. Another possibility would be the establishment of a colony, using birds reared by GONHS, on
the cliffs of the east side of the Rock or on Windmill Hill. These aspects will be considered in more detail
in a separate study (Perez, in prep.)
Class: Aves Order: Falconiformes Family: Falconidae
PEREGRINE FALCON
Falco peregrinus brookei
Figure 3: Peregrine Falcon Falco peregrinus (F. Barrios)
General Description
In Gibraltar the Peregrine is of the Mediterranean subspecies brookei, which is slightly smaller than the
nominate race. It nests on cliff ledges. The female lays a clutch of 3–4, sometimes 5 eggs in late March
and April, which hatch after an incubation period of approximately 30 days. The young leave the nest a
month later and soon disperse to colonise other areas.
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The nominate species is afforded a favourable ‘secure’ status in Europe by Birdlife International (2004),
that had been previously classified it as ‘rare’. Nevertheless the species is included in Annex I of the EU
Wild Birds Directive, Appendix III of the Bern Convention, and included in the Emerald Network that aims
to establish a network of ‘areas of special conservation interest’.
Global Distribution
The Peregrine has an almost worldwide distribution, being found on every continent except Antarctica.
Local Distribution
The Peregrine is widely distributed throughout Gibraltar, with up to seven pairs nesting in 2005. The
nests are distributed along the cliffs, from the North Face, East Side cliffs, Europa cliffs and Camp and Little
Bay cliffs. This is an unprecedented concentration of breeding birds, so that Gibraltar clearly contributes
significantly to the Peregrine population of the region.
POPULATION TREND: Stable, with slight recent increase.
Threat
The Peregrine Falcon is highly coveted as a falconer’s prize and as such has not escaped the
unscrupulous eyes of certain individuals in Gibraltar in the past. One particular pair’s nest was ransacked
and the chicks taken on several occasions in the 1980s and 1990s. This practice seems to have stopped,
but in 2003 a rope was reported dangling down close to the nest site and the police were called in to investigate.
The disturbance to nests and temporary or permanent loss of nest sites as a result of cliff stabilisation
works is a concern.
A potential threat to this species is the use of poison to control the growing population of feral pigeons,
a practice that has been suggested in the local press. This would be unreasonable, as the possibility of the
poisoned pigeons passing into the food chain of other wildlife, including the Peregrine is wholly unacceptable.
Action
The Environmental Agency and other pest control bodies on the in Gibraltar must only use measures in
controlling pest species that do not involve the use of poisons or other agents that may be detrimental to
the survival of other species of wildlife.
Construction projects should not be sited at the base of cliffs. Any works to cliffs must ensure that they
are both carried out outside the nesting season and that they do not destroy or block access to actual or
potential Peregrine nest sites.
Continual monitoring and research, and a vigilance of all sites during the breeding season, particularly
those within easy reach should be maintained annually, together with breeding surveys of this species to
assess their reproductive success. This is currently undertaken by GONHS.

Class: Aves Order: Galliformes Family: Phasianidae
BARBARY PARTRIDGE
Alectoris barbara
Figure 4: Barbary Partridge Alectoris barbara (E. Shaw)
General Description
A shy species feeding on shoots, fruiting shrubs, seeds and invertebrates. The female lays 10–14 eggs
in a shallow scrape on the ground between March and May. The chicks hatch in late May and June in
Gibraltar and are capable of taking short flights at 7–10 days. In the winter they form coveys of up to eight
birds.
Global Distribution
Found only in the western Palaearctic, almost entirely within the north-western African countries of
Morocco, Algeria, Tunisia and Libya, and in the Canary Islands. In mainland Europe it is found only in
Gibraltar. A small population of the species is also established on the island of Sardinia, where it is presumed
the species was introduced in the mid-18 th century (Snow & Perrins, 1998).
Local Distribution
The bird is located mainly on open areas in the Upper Rock Nature Reserve, the Lower Slopes and the
Talus Slope with its main stronghold on Windmill Hill Flats. It has recently been seen on the Great Sand
Slopes, a restored habitat that will greatly improve the expansion and conservation of this species.
POPULATION TREND: Unknown although probably stable.
Threat
Several factors are affecting the conservation of the species. Amongst the most important of these is
habitat loss within the Upper Rock Nature Reserve. Open ground, the bird’s preferred habitat, has been
diminishing at a rapid rate with the loss of important firebreaks that provided the birds with foraging and
breeding grounds. The loss of the Bruce’s Farm firebreak and the open ground within the MoD aerial farms
on the Upper Rock, encroaching vegetation on existing firebreaks and the loss of open habitat on Rock Gun
and the adjacent Lower Slopes are the main factors that are affecting the population of this species.
It is difficult to assess the status of the Barbary Partridge in such dense habitat, but there seems to have
been a decline in the population of the species on the Upper Rock in the last decade (pers. obs.). Another
contributing factor to this decline must surely be the rising population of feral cats on the Upper Rock and
in other areas around Gibraltar. Tourist sites at St. Michael’s cave, the Cable Car top station and the Upper
Galleries have resident populations of feral cats that are encouraged by food handouts by tour operators,
site employees and others. Young flightless partridge chicks are easy prey for these predators. Predation
by Yellow-legged Gulls has also been observed.
The presence of chicken coops on the Upper Rock is also worrying. Chickens will compete with par-
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tridges for food. Moreover, when these animals are allowed to wander freely they may come into contact
with the partridges that may contract undesired avian pathogens from these known carriers of disease.
Action
The Barbary Partridge’s very restricted distribution in Europe has resulted in the choice of this species
as a flagship bird species for Gibraltar and as the GONHS emblem. It is therefore imperative that the welfare
and survival of this species in Gibraltar is secure.
The implementation of the environmental management plan and recommendations as set out in the
‘Upper Rock Nature Reserve, A Management & Action Plan’ (Perez & Bensusan, 2005), to effectively tackle
habitat succession, and an effective firebreak policy with regular maintenance would go a long way
towards improving the status of the Partridge.
A cat-culling programme must be established for the Upper Rock Nature Reserve and in other areas of
Gibraltar where the Barbary Partridge and other wildlife are at risk.
A research and monitoring programme should be implemented, in order to assess the status of the
species and gauge the success of the environmental management and cat control programmes in relation
to the recovery and conservation of the Barbary Partridge.
This species should be included in public awareness campaigns as the flagship bird species of
Gibraltar.
Class: Aves Order: Strigiformes Family: Strigidae
EURASIAN EAGLE OWL
Bubo bubo
Figure 5: The Eurasian Eagle Owl Bubo bubo. (E. Shaw)
General Description
The Eurasian Eagle Owl is the world’s largest owl with a wingspan of 150–200cm. The owl breeds
between February and July with the female laying a clutch of 1–3 eggs. Generally nocturnal in its habits,
it feeds on a wide variety of prey items including medium-sized mammals, such as rabbits, and birds. In
Gibraltar they have been feeding successfully on Yellow-legged Gulls. The local pair raised the maximum
three young in what appeared to be their initial breeding attempt in 2005.

The Eagle Owl is protected under the Nature Protection Ordinance (L/N 11 of 1991), and is a species
of European conservation concern that is afforded SPEC 3 category by Birdlife International (2004). It is
an Appendix III species under the Bern Convention, requiring the Contracting Party to take appropriate and
necessary legislative and administrative measures to ensure its protection. It is also listed under Annex I
of the Birds Directive 79/409/EEC, which requires that Special Protection Areas (SPAs) be designated for
the species. The Upper Rock Nature Reserve and the owls’ feeding sites on the East side have been proposed
as candidate SACs under the Habitats Directive.
Global Distribution
The Eagle owl is widely distributed throughout Europe, Russia, Asia and the Middle East. The
European breeding population is relatively small, having undergone a severe decline during the 1970-1990.
It has since recovered, although numbers are still below 1970 figures (Birdlife International 2004).
Local Distribution
Extinct as a breeding species in Gibraltar since the 1920s (Garcia 2006), a pair was discovered breeding
in the spring of 2005, and might have been present previously, since the nocturnal habits of this owl and
its shy behaviour make it difficult to locate. The birds nest in small caves on the east cliffs above Catalan
Bay, and forage widely along the Great Sand Slopes and the Talus slope, as was seen by the widely scattered
remains of Yellow-legged Gull chicks present (pers. obs.).
Threat
The proposed development of a funicular railway in the area above the nest site, just after it had
recolonised Gibraltar would have resulted in its extinction again. Thankfully the proposal was rejected by
the Development & Planning Commission after a lengthy campaign.
The use of poison to control rats around the tourist sites located on the Upper Rock is potentially fatal
for the Eagle Owls and other birds of prey that may consume these animals.
Action
The Environmental Agency must be instructed to refrain from using poison indiscriminately in Gibraltar.
There are non-toxic agents and trapping methods that will eradicate rat infestation that will not affect
wildlife. These should preferably be used.
Careful monitoring of this pair is required and the establishment of the proposed Biological Reserve
(Perez & Bensusan, 2005), within the confines of the Rock Gun/Middle Hill area, that will restrict unescorted
access to the general public, would ensure minimal disturbance to the breeding site of this species,
which may lead to the establishment of further pairs on the Rock.
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Mammals
Class: Mammalia Order: Cetacea Family: All
ALL CETACEANS
Figure 6: Common Dolphins Delphinus delphis. (E. Shaw)
General Description
Locally, there are breeding nurseries of both Striped Dolphins Stenella coeruleoalba and Common
Dolphins Delphinus delphis within the Bay of Gibraltar (Shaw 1998). They feed on cephalopods, crustaceans
and bony fish. The mating season is in autumn, with a gestation of between 12-13 months, a nursing
period of 16 months and a four-year calving interval, (MarineBio.org).
Global Distribution
Most of the cetacean species encountered in and around Gibraltar and its waters are those of warmtemperate
and tropical seas throughout the world including the Mediterranean Sea, Pacific Ocean, Atlantic
Ocean, Indian Ocean, Caribbean Sea, and the northern Gulf of Mexico.
Local Distribution
Local Dolphin populations are found at the head and the central part of the Bay of Gibraltar, with large
numbers of local and migrant schools frequently encountered in the Strait and the eastern side. Whales
often enter the Bay but are most often seen in the Strait of Gibraltar and the waters on the eastern side of
the Rock. These include Fin Whales Balaenoptera physalus, Minke Whales Balaenoptera acutorostrata
and Sperm Whales Physeter macrocephalus, of which there is a small resident population in the Strait.
POPULATION TREND: Unknown, although all local species are considered vulnerable.
Table 2: List of cetacean species encountered in Gibraltar waters.
DELPHINIDAE
Common Dolphin Delphinus delphis
Long-finned Pilot Whale Globicephala melas (melaena)
Risso's Dolphin Grampus griseus
Orca or Killer Whale Orcinus orca
Striped Dolphin Stenella coeruleoalba
Bottle-nosed Dolphin Tursiops truncatus
PHYSETERIDAE
Sperm Whale Physeter macrocephalus
ZIPHIDAE
Cuvier's Beaked Whale Ziphius cavirostris
BALAENIDAE
Northern Hemisphere Minke Whale Balaenoptera acutorostrata
Fin Whale Balaenoptera physalus
Humpback Whale Megaptera novaeangliae

Threat
The main threats are as follows:
• Disturbance from increased shipping activity, including dolphins spotters
• Habitat loss and degradation
• Contamination and pollution
• By-catch in fisheries
The main threat to the populations of dolphins found inside the Bay of Gibraltar is the increased shipping
activity and bunkering, allowing for fewer areas where the dolphins can roam in peace.
This peace is further threatened by the uncontrolled activity of up to five dolphin tour operators based
in Gibraltar and La Linea, some of which frequently disturb the dolphin pods. Add to this the increased
potential of oil spillage and pollution in the Bay and the welfare and survival of the dolphin species in the
Bay is greatly compromised.
Habitat loss may become a problem with the increasing amount of reclamation in the Bay, outside harbour
areas, particularly in relation to the ports of Algeciras and La Linea. Similarly industrial and commercial
activities around the Bay are a constant source of pollution, with oil-related activity in particular risking
a major oil spill.
Although the use of drift nets has been outlawed in the Mediterranean, the species are occasionally
caught in drift and seine nets, when they are quickly despatched by fishermen. They are also sometimes
caught within the tuna traps that are located at the entrance to the Strait. Dead dolphins with cut fins and
tails are sometimes washed up on our beaches. Whale casualties as a result of the collision with ships and
their propellers occasionally turn up in the Bay of Gibraltar and on the shores of the Rock.
The use of nets is also forbidden under the Nature Protection Ordinance, but despite this a local agreement
with fishermen from La Linea and Algeciras allows a maximum number of four boats at any one time
to fish with certain nets (those in keeping with European law) no closer than 350m from the shore. This
arrangement is often abused and nets over 1 km long can be seen off-shore, while seine nets are used
inshore, in areas such as Rosia and Little Bay and Governor’s Beach. These practices are not possible in
nearby Spanish waters because of the increased shipping on their side of the Bay and because their coastline
was declared a marine Nature Reserve in 2003 within the Párque Natural del Estrecho as part of the
Red de Espacios Naturales Protegidos de Andalucía.
Action
There is no easy solution to the increase in shipping activity taking place in the Bay of Gibraltar.
Nevertheless the foraging and breeding areas of these dolphins should be identified and the Port authorities
in Gibraltar and Algeciras notified, so that exclusion zones can be declared or at least they can keep
disturbance in these areas to an absolute minimum.
The activities of the Dolphin tour operators must be controlled with a strict code of conduct. The
Dolphins must be allowed to approach the boats as they please and not vice versa. Speed of the vessels
must remain to an absolute minimum and harassment of the animals must not be allowed, with minimum
distances and mobile exclusion zones around groups of dolphins and time intervals between which the
same group may not be approached. A draft protocol covering all these aspects was prepared by GONHS
and presented to the Port Authorities in 1999 but no progress has been made (Shaw 1998).
The Port authorities must ensure adequate standards to avoid the possibility of potential oil and fuel
spillage and contamination and pollution of our waters.
The laws prohibiting the use of nets within Gibraltar waters must be enforced
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Class: Mammalia Order: Primates Family: Cercopithecidae
BARBARY MACAQUE
Macaca sylvanus
Figure 7: Barbary Macaques Macaca sylvanus. (J. Martinez)
General Description
The Barbary Macaque belongs to the old world monkeys, and is mistakenly referred to as Barbary or
Rock “Ape”. Although it lacks a tail, it is a true monkey. The males are large, reaching over a metre in
length, with strong features including long canine teeth and powerful jaws. Females are slightly smaller and
less muscular. Mating occurs during the late autumn and winter with young born in late spring and summer
after a gestation period of about five months. These are social animals that usually live in groups of
10-40 individuals and feed on a variety of plant shoots, fruit and roots and small invertebrates.
Global Distribution
Once found extensively along montane forests in Algeria, Morocco and Tunisia, the species has
declined dramatically with only 23% of the global population found in small colonies in Algeria and the
remainder mainly in the Middle Atlas of Morocco and smaller populations in the Rif Mountains and High
Atlas (Oates, 1997), with a total global population of no more than 10,000 (Mouna & Ciani, 2006). Also
found in the wild in Gibraltar where they were most probably introduced in historical times (Shaw & Cortes,
2006), and where the species is doing well.
Local Distribution
The population of Barbary Macaques in Gibraltar was 248
individuals in January 2006. They are mainly distributed in six
groups within the Upper Rock Nature Reserve, although some
foraging occurs outside the boundaries of the Reserve.
POPULATION TREND: Increasing in Gibraltar.
Decreasing elsewhere.
Apes Den
Middle Hill
Anglian Way
Faringdon Battery
Prince Phillips Arch
Lathbury Barracks
Observations outside normal range
Figure 8: Home range of the Barbary Macaques 2004
(Perez & Bensusan 2005, Shaw & Cortes, 2006).

Threat
The Barbary Macaque is the flagship mammal species of Gibraltar and the main tourist attraction within
the Upper Rock Nature Reserve, and is under no threat. In fact the species has increased its population
from 33 individuals in two groups in 1970 (when most culling by the Military stopped), to the present
240 in six groups.
This species is classified as vulnerable by the World Conservation Union in the IUCN Red Data List
2002, and listed under Appendix II of CITES. Wild populations in North Africa are shrinking rapidly due to
habitat loss, overgrazing and human disturbance. Nevertheless the local population of the Macaques is
doing so well that Macaques have reached pest proportions. Some groups are now foraging in residential
areas while others are pilfering the refuse dumps.
The Barbary Macaque is both a globally endangered species that needs protection and a pest species
that has an adverse effect on local biodiversity. The species causes extensive erosion to cliff faces and
slopes and uproots numerous plant species in its foraging sprees. This is happening in particular sensitive
areas of Rock Gun and Middle Hill, the area around Prince Phillip’s Arch, Anglian Way and O’Hara’s Battery,
where many rare species of plants have disappeared and others are under threat from the constant foraging
of these animals.
A clear example of the damage done can be seen at the Ape’s Den, where the cliff area is devoid of any
vegetation and even the olive trees that grow in the area have suffered from the constant swinging and
branch-bending displays of the males.
Action
The ongoing population explosion has reached unsustainable levels in Gibraltar. They have also
extended their range to include areas where interaction with the human population has been inevitable, and
has already resulted in numerous public complaints. They regularly ransack open rubbish bins in the Calpe
area and are also fed illegally by the residents in the area (pers. obs.).
Implementation of the recommendations and the effective control and management of the Barbary
Macaques as stipulated in the report ‘Upper Rock Nature Reserve, A Management and Action Plan’ (Perez
& Bensusan, 2005), which summarises past consultation and representations by GONHS, is a priority. This
would include the removal of excess groups, through exportation wherever possible or through a culling
programme to limit the numbers within the Nature Reserve to a manageable number, and should exclude
a group that is free from human interaction.
Macaque proof bins should be incorporated in residential areas and illegal-feeding laws should be
enforced, both within the Nature Reserve and in other areas where macaques frequently roam.
Informal proposals for a new macaque site at Tovey Battery are unwise, as this particular location will
bring a new group within a few hundred metres of the already problematic Calpe area of the upper town,
and exacerbate an ongoing problem. It is better to maintain those sites that are already occupied by
macaque groups that lie well away from human habitation.
The establishment of new groups to accommodate the tourist industry is unreasonable, placing excessive
pressure on existing groups and creating further environmental damage through the foraging exploits
of the animals. Facilities at established Macaque tourist points should be expanded instead of creating new
sites.
Further reading
• Hodges, J.K & Cortes, J. (eds) (2006) The Barbary Macaque, Biology, Management and
Conservation. Nottingham University Press. Nottingham.
• Oates, J,F. (1996) African Primates: Status Survey and Conservation Action Plan. IUCN, Gland,
Switzerland.
• Perez, C. E. & Bensusan, K. E. (2005) Upper Rock Nature Reserve. A Management and Action Plan.
Barbary Macaques, pp165-174. The Gibraltar Ornithological & Natural History Society. Gibraltar.
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Class: Mammalia Order: Carnivora Family: Canidae
RED FOX
Vulpes vulpes silacea
Figure 9: Red Fox Vulpes vulpes ssp. silacea (E. Shaw)
General Description
This carnivore reaches sexual maturity in its first year, with breeding taking place in January and
February. The cubs are born after a gestation period of approximately 52 days, with a litter of between one
and seven individuals. Red Foxes are generalists that inhabit a great variety of habitats and adapt well to
human presence.
Global Distribution
Distributed throughout the northern hemisphere reaching the Arctic Circle, the Red Fox is the most
widespread of all carnivores. It is widely distributed throughout the Iberian Peninsula and North Africa.
Local Distribution
By the early 1980s the Red Fox became extinct locally, but GONHS developed a reintroduction programme,
as part of the Yellow-legged Gull control programme. A captive breeding programme, using foxes
from Spain, commenced in 1995 but was unsuccessful. In 2003 the animals were released on the Rock
with another fox released in early 2005. At present the species is present in the southern area of the Upper
Rock Nature Reserve, Windmill Hill and the Europa area.
Threat
Rodenticide is sometimes used by the Environmental Agency on the Upper Rock Nature Reserve, especially
within St. Michael’s Cave and the Great Siege Tunnels. This poses a serious threat to the survival of
species that consume rats as part of their diet. Similarly residents on the Upper Rock may be using this
form of rodent control, posing a serious threat to the Fox.
Action
As the captive breeding programme proved unsuccessful, a reintroduction programme should continue
using available animals from Spain that would be released in the wild, after health checks and vaccinations.
Apart from increasing our biodiversity, the animal is well suited to the habitats on the Upper Rock and
peripheral areas where it would benefit from and have a great impact on the current Yellow-legged Gull population.
A total ban on the use of rodenticide by the Environmental Agency and local residents must be
applied if species such as the Fox, Eagle Owl and Raven are to survive within the Nature Reserve. The
use of environmentally friendly methods of controlling rodent populations, such as trapping and non-toxic
lethal baits should be encouraged.

Class: Mammalia Order: Lagomorpha Family: Leporidae
EUROPEAN RABBIT
Oryctolagus cuniculus
Figure 10: The European Rabbit Oryctolagus cuniculus. (E. Shaw)
General Description
The Rabbit is a species that can breed throughout the year. The reproductive cycle is therefore dependent
on an abundant supply of quality food linked to favourable wet climatic cycles. These periods range
from November through to early June, when after a period of approximately 20-30 days the Rabbit will give
birth to between three and six individuals, and may breed again up to four times within the same year.
Global Distribution
Originally native to Iberia and the western Mediterranean, the European Rabbit has now been introduced
to many parts of the world.
Local Distribution
Rabbits are distributed mainly on the Upper Rock and Windmill Hill flats. Although they seem more
common on Windmill Hill, this may be due to the more open nature of the vegetation at this site.
POPULATION TREND: Decreasing.
Threats
Although a detailed survey of the status of Rabbit populations in Gibraltar has not been carried out, it is
evident to local naturalists based on casual encounters that the population of Rabbits on the Upper Rock
has become depleted. This is probably due to a combination of factors. The increasingly tall and dense
nature of much of the vegetation of the Upper Rock clearly does not suit this species’ ecology. In addition
the number of feral cats on the Upper Rock has seen a dramatic increase in recent years (Perez &
Bensusan 2005). Cats are known to prey on Rabbits (Bayly, 1975), and these could have a serious effect
on a population that is already suffering as a result of habitat loss.
Rabbits on Windmill Hill are frequently encountered and are not uncommon. However, this population
is small given the size of the area. Increased isolation poses a serious threat to what seems to be
Gibraltar’s most healthy Rabbit population. In this sense the development of the Lathbury area has the
potential to jeopardise the most important population of the species on the Rock, in effect isolating the population
further. Feral cats are also a problem on Windmill Hill.
Pet Rabbits have been released in some areas of Gibraltar, including Windmill Hill, the Upper Rock and
recently on the Europa Foreshore. These have the potential to interbreed with our wild stock, contaminating
the local gene pool.
Rabbits are known to do better in wet years (Palomo & Gisbert 2000). Climate is known to be changing,
with most of Europe becoming hotter and drier (EEA 2004). Climate models predict an increase in temperature
and decrease in rainfall for Gibraltar and the Mediterranean (Sanchez et al. 2004). If correct, this
will have a negative impact on the reproductive output of the Rabbit on the Rock.
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Action
The removal of feral cats from the Nature Reserve and Windmill Hill would serve to improve the possibility
of a population increase. Firebreak maintenance and clearing, and the introduction of a habitat management
workforce as recommended by Perez & Bensusan (2005) would substantially benefit the preferred
habitat of Rabbits. Feral domestic rabbits should be removed and the release discouraged by publicity as
well as legal means, as it is in contravention of the Nature Protection Ordinance.
Further Reading
• Anderson, I., (1995) "Alien predators devastate Australian wildlife". New Scientist, Vol 145, No 1962.
• Bayly, C. P., (1975) "Food habits of the feral house cat in the Woomera area" (unpublished).
Class: Mammalia Order: Chiroptera Family: Vespertilionidae
SOPRANO PIPISTRELLE
Pipistrellus pygmaeus
Figure 11: Soprano Pipistrelle Pipistrellus pygmaeus.
General Description
Pipistrellus pygmaeus differs from the very similar P. pistrellus primarily in vocalisations: the former calls
at between 49.2–57.6 kHz and the latter between 41.6–50.8 kHz. The species is found in varied habitat
types including urban areas, where it can be seen catching insects around street lights. P. pygmaeus shelters
in rock fissures, trees, nest boxes, buildings and occasionally caves. Breeding takes place in the
spring with the young born in late May and June. Females lactate until August by which time they leave
the young to fend for themselves (Palomo & Gisbert 2000).
All Bat species are protected under the Nature Protection Ordinance (1991) and under the Bonn
Convention in the Agreement on the Conservation of Populations of European Bats (EUROBATS).
Global Distribution
Mainly distributed in southern and central Europe.
Local Distribution
Poorly known, although observed primarily in the Alameda Gardens and the town area.
POPULATION TREND: Stable to decreasing.
Threats
The redesigning of roofs in the town area has had an impact on the Pipistrelle population, which frequently
used the older, tiled roofs as roost sites.
Action
A public awareness and educational campaign on the status and predicament of Bat populations in
Europe, and their contribution in eliminating insects, together with the promotion and erection of bat boxes
in urban and suburban areas, would improve the concept that people have of these creatures. Planners
and developers must be made aware of the potential presence of bats in buildings alter plans to avoid disturbance.
New buildings should require provision for potential bat roosts.

Class: Mammalia Order: Chiroptera Family: Miniopteridae
SCHREIBER’S BAT
Miniopterus schreibersii
Figure 12: Schreiber’s Bats Miniopterus schreibersii. (J.Cortes)
General Description
Breeding of the Schreiber’s Bat takes place in the autumn and females can suspend gestation until after
hibernation. The offspring are born at the end of June and July with only one young per female. After two
to three months the offspring are ready to fly, and are capable of surviving up to 15 years.
Global Distribution
A subtropical species distributed throughout Europe, Africa, Asia and Australia. The taxon known until
recently as Miniopterus schreibersii has undergone a revision, and the subspecies inhabiting many parts of
Africa, Australia and Asia are now considered different species by some authors.
Local Distribution
The Schreiber’s Bat was once the most numerous bat in Gibraltar. During the 1960s, this bat was widely
distributed in many of the Rocks’ larger caves and tunnels. Palao (1969) recorded over 7,800 individuals,
with Martin’s Cave holding the largest colony of 5,000. By the early 1980s approximately 500 were left
and this colony disappeared shortly after. A small colony of between 20-40 individuals was rediscovered
recently in a tunnel close to O’Hara’s battery and is the only known group of the species in Gibraltar. There
has been a ringing control of a Schreiber’s Bat originally ringed in Benalmadena, Malaga, Spain, about
100km north-east of Gibraltar.
POPULATION TREND: Decreasing; considered locally endangered.
Threats
Disturbance to the bats’ historical caves was thought to have been the main cause of the decline and
subsequent extinction of the species on the Rock. Evidence of fires lit within the cave to disturb bats intentionally
was found. The succession of much of the vegetation on the Upper Rock into high maquis has seriously
affected this species ability to feed in open areas such as garigue, which it prefers. In 2001, 2002
and 2003 many bats of this species died throughout Iberia, apparently as a result of a viral disease, which
was however not detected in Gibraltar.
The massive decline in the population of this species is difficult to attribute to these factors alone. The
possibility of another agent affecting the species has to be considered. Indiscriminate use of pesticides in
Spain and Morocco may be the cause, as there seems to have been a decline in insect populations on
which animals depend.
Action
Similar action to the former bat species including the implementation of the Cave Management Plan
proposed by Perez & Bensusan (2005), to ensure the protection and conservation of suitable breeding and
roosting caves on the Rock. Management of the habitat of the Upper Rock to allow more open areas, as
well as protection of existing open areas such as the Great Sand Slopes, Windmill Hill and associated areas
are of vital importance.
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Flowering Plants
Class: Angiospermae Order: OrchidalesFamily: Orchidaceae
ALL ORCHIDS
Figure 13: Bumble-bee Orchid Ophrys bombyliflora. (L. Linares)
General Description
The orchids found in Gibraltar are perennial plants that grow from tuberous roots. They produce large
numbers of minute seeds, which in order to germinate successfully, must land on favourable ground containing
a fungus with which it will form a symbiotic relationship. The seeds are devoid of food reserves, and
will obtain the necessary nutrients from the fungus until the first leaves are produced. Anything from two
to fifteen years may elapse from germination to production of the first leaves. This will depend on the environmental
conditions and on the species concerned.
Orchids grow best on open habitats where there is little or no overgrowth. At the same time they prefer
humid ground conditions and are often found on soil and rocky outcrops where there are mosses and
ferns. In Gibraltar these conditions are found in clearings and rocky outcrops within the maquis, on cleared
firebreaks, and along footpaths and roadsides.
Global distribution
Orchids are found throughout the tropical and temperate regions of the world. The genera found in
Gibraltar are typical of those found in temperate and northern regions of Europe, and in African and Asian
countries bordering the Mediterranean.
Local distribution
The majority of orchids in Gibraltar are found in the area known as the Lower Slopes, which are located
below the 200m contour and above the upper town. Here they can be found mainly on the north-facing
slopes of the three gullies that cross the area from east to west. A few scattered plants can also be found
on rocky outcrops and other open areas within these Lower Slopes. Elsewhere on the Upper Rock orchids
can be found along footpaths and roadsides, and also on rocky outcrops and clearings.
POPULATION TREND: Local populations have been declining over the last twenty years or so. A small
population of the Bumble Bee Orchid was only discovered in 2006 in the Convent Gardens, after an absence
of over fifteen years and the Pyramidal Orchid, Anacamptis pyramidalis has not been seen since 1990.

Table 3: Orchid species that have been recorded in Gibraltar.
Orchids
Pyramidal Orchid Anacamptis pyramidalis
Two-leaved Gennaria Gennaria diphylla
Bee Orchid Ophrys apifera ssp. apifera
Bumble Bee Orchid Ophrys bombyliflora
Brown Bee Orchid Ophrys fusca ssp fusca
Yellow Bee Orchid Ophrys lutea ssp. lutea
Mirror Orchid Ophrys speculum
Sawfly Orchid Ophrys tenthredinifera
Small Tongue Orchid Serapias parviflora
Autumn Lady's Tresses Spiranthis spiralis
Threats
Orchids do not take kindly to disturbance, and as a result of repeated and indiscriminate clearing of
roadsides along the Upper Rock practically all the orchids that used to grow along these cleared roadsides
have been exterminated. Those growing on the Lower Slopes and along footpaths suffer from the effects
of overgrowth and spread of the surrounding vegetation. The spread of invasive species such as Bermuda
Buttercup Oxalis pes-caprae and Bear’s Breeches, Acanthus mollis has also played a part in the decline.
Action
Roadsides and footpaths must be kept clear of overgrowth. This should involve the cutting back of overgrown
shrubs, but not the removal of ground vegetation.
All firebreaks have to be cleared annually, and this should be done at the end of the main flowering season,
once the plants have set seed. This includes the firebreak around Bruce’s Farm, which has not been
cleared for many years and is now seriously overgrown. Firebreak boundaries should be cut back to avoid
encroachment.
A management programme should be drawn up for the Lower Slopes, so that the density of the
encroaching maquis vegetation could be reduced. This would re-create the open areas that once existed
there.
Invasive plant species should be removed.
Ex-situ conservation should be encouraged through cultivation in the Gibraltar Botanic Gardens. None
are grown at present.
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Class: Angiospermae Order: Centrospermae Family: Caryophyllaceae
GIBRALTAR CHICKWEED
Cerastium gibraltaricum
Figure 14: Gibraltar Chickweed Cerastium gibraltaricum. (L. Linares).
General Description
The Gibraltar Chickweed is a loosely tufted woody perennial that flowers between April and June. The
species grows on cliffs and in rocky areas.
Global Distribution
Endemic to Gibraltar.
Local Distribution
The Gibraltar Chickweed is found mainly on the North Face, which is the only population that appears
not to be threatened at present. It also grows in the Rock Gun area, where it grows on stony ground and
in the limestone crevices. Also encountered along Martin’s Path and Mediterranean steps, and recently
found on the north-facing cliffs below Devil’s Gap.
POPULATION TREND: Decreasing, considered vulnerable.
Threats
Recent threats have come from the proposed development of part of the Rock Gun area as the site for
a Funicular railway, which would have led to the problem of thousands of visitors wandering around the site.
This development was finally rejected by the Development and Planning Commission in May 2005, but puts
into question the relative ease with which the Nature Protection Ordinance 1991, Upper Rock Nature
Reserve Designation Order and the recommendations of The Gibraltar Development Plan (1991) can be
disregarded by developers.
Another serious threat to the species comes from the foraging of a herd of goats in the Rock Gun area,
and another herd distributed along the cliffs from Royal Anglian Way to the Lower Slopes in a potential area
for this species. Further foraging from Barbary macaques in the Rock Gun area and a traditional site for
this species from Prince Phillip’s Arch to Douglas Path will seriously affect the survival of this species.
The large population on the North Face would be threatened if cliff works were ever permitted there.
Action
Although the Gibraltar Chickweed is afforded protection under Schedule 3 of the Nature Protection
Ordinance and is found within the Upper Rock Nature Reserve, a candidate SAC (Special Area of
Conservation under the Habitat’s Directive) and a site that was afforded Policy Z19 under The Gibraltar
Development Plan 1991, the species is one of the most threatened in Gibraltar. In this context the action
necessary at this stage is to emphasize the legal and environmental responsibilities that Gibraltar has to
ensure the protection not only of the protected species, including the Gibraltar Chickweed, but also the conservation
of their prime habitats for the survival of the species.

To ensure this, the implementation of the recommendations of Perez & Bensusan (2005), to establish
a biological reserve within the area denominated as Rock Gun and Middle Hill would be a sensible step forward.
The elimination of the herd of goats remains a priority, as is the exclusion of Barbary macaques from
the top of Rock Gun.
Cliff work must not be carried out on the North Face.
Ex-situ conservation should be encouraged through cultivation and banking of seed in the Gibraltar
Botanic Gardens. The species is not cultivated at present.
This species must be included under Annex II of the Habitats Directive 92/43/EEC and in the World
Conservation Union’s ‘IUCN Red Data List of Threatened Species.
Class: Angiospermae Order: Centrospermae Family: Caryophyllaceae
GIBRALTAR CAMPION
Silene tomentosa
Figure 15: Gibraltar Campion Silene tomentosa.
General Description
A woody-based perennial that flowers from April to May. The flowers emit a deep fragrant scent at night
and on cloudy days, suggesting that this plant is pollinated by nocturnal insects.
Global Distribution
This species is endemic to Gibraltar: i.e. its global distribution is restricted to the Rock.
POPULATION TREND: Extinct in the wild, some re-introduced plants survive. Critically endangered.
Local Distribution
Discovered and described by Otth in 1824 (and later by Boissier in 1838 (S. gibraltarica Boiss.) who
found it growing on the north and east cliffs of the Rock). There were no recent sightings in the wild until
1979 and 1985, when a few plants were observed by L. Linares and A. Harper (Linares et al. 1996). This
species was widely searched for in subsequent years and deemed extinct, until its rediscovery in 1994,
again in the Rock Gun area, from where seeds were taken. All the records of this species have been found
above 240m in the specified area. No other wild plants have been seen since, and attempts at reintroduction
in favourable areas have so far been of limited success, with only a few plants successfully establish.
Threat
Recent submissions were made to, and rejected by, the Development and Planning Commission pro-
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posing the development of much of the species’ historical distribution. This development is not compatible
with the aims of wildlife conservation since it destroys the integrity of an extremely important habitat.
The species is conservation–dependent, with a population of about 60 in the Gibraltar Botanic Gardens
(where it germinates well) and in several other European Botanic Gardens which have been sent material
from Gibraltar. The apparent inability of the species to spread naturally in the wild, apparently due to difficulty
in germination outside a controlled environment is cause for concern.
Action
On its rediscovery attempts were made to ensure the survival of the species. Cuttings were taken and
sent to Kew in London, where the type specimen is housed, and seeds were sent to the San Fernando
Botanic Gardens in Cádiz, where the species is doing well. Seeds germinated successfully in the Gibraltar
Botanic Gardens, and the species was transferred to some of the beds. A reintroduction programme was
attempted, with several plants transplanted to suitable localities and habitats. North-facing cliffs around the
top of Mediterranean Steps, Windmill Hill and Rock Gun were chosen but most of the plants did not regenerate
the following year, and only that at the top of Mediterranean Steps survived. Attempts have continued
with more being planted out in Windmill Hill in winter 2005-2006.
Attempts at reintroduction of this species into the wild should continue on an annual basis until a viable
population is re-established. In the meantime ex-situ conservation should be encouraged through cultivation
and banking of seed in the Gibraltar Botanic Gardens. A search for other wild plants should be undertaken.
No development that poses a threat to any aspect of wildlife conservation within the entire known historical
distribution of Silene tomentosa should be entertained.
This and other important plant and animal species were left out of the Habitats Directive through lack
of reference to Gibraltar experts during drafting. As possibly the rarest plant in Europe, it is therefore imperative
that this species is included under Annex II of the Habitats Directive 92/43/EEC. It also requires inclusion
in the World Conservation Union’s ‘IUCN Red Data List of Threatened Species’.
Class: Angiospermae Order: Tubiflorae Family: Labiatae
GIBRALTAR THYME
Thymus wildenowii
Figure 16: Gibraltar Thyme Thymus wildenowii. (L. Linares).
General Description
The Gibraltar Thyme is a woody and much-branched aromatic dwarf shrublet that grows from limestone
crevices and old stone walls, and flowers between April and July.

Global Distribution
In Europe, this species is known only from Gibraltar, although there are unconfirmed records in the San
Roque area (Valdes et al. 1987). Although it has been stated that the species is also found in North Africa,
its exact status remains ambiguous and there seems to be no indication as to where it is currently found in
Morocco.
Local Distribution
This species is quite common and widespread throughout the Upper Rock, mainly found growing from
limestone crevices along most roads, and also on old walls such as Charles V Wall. It may also be found
wherever there are rocky outcrops on the western and southern slopes, along the upper ridge, and along
Martin’s Path and Mediterranean Steps, and even down along Hole in the Wall area at Europa Advance.
Scattered individuals may even be found on old walls in the Town.
POPULATION TREND: Stable.
Threats
The species is widespread enough not to be under any specific threat, but those growing along the
roadsides of the Upper Rock are prone to removal whenever the roadsides are scraped clean of vegetation.
A possible future threat would be the removal of all vegetation from the surfaces of old walls such as
Charles V Wall. This should not occur however, since these herbaceous plants do not pose a threat to the
structure and integrity of the walls, and add character to the same (C. Viagas, pers. comm.).
Action
The employees of cleaning contractors must be instructed not to remove vegetation growing from the
roadside surfaces above ground level, and restrict themselves to pruning back small trees and shrubs that
might interfere with traffic. The relevant authorities must be made aware of the fact that old walls harbour
populations of these plants (as well as certain other species such as Linaria tristis, Campanula velutina and
Helichrysum rupestre), which do the walls no harm, and should not be removed.
Ex-situ conservation should be encouraged through cultivation and banking of seed in the Gibraltar
Botanic Gardens. There is a small cultivated population at present.
This species should be included under Annex II of the Habitats Directive 92/43/EEC.
Class: Angiospermae Order: Leguminosae Family: Papilionaceae
GIBRALTAR RESTHARROW
Ononis natrix ssp. ramosissima var. ramosissima
Figure 17: Gibraltar Restharrow Ononis natrix ssp. ramosissima var. ramosissima. (L. Linares).
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General Description
The Gibraltar Restharrow is a much-branched, woody-based shrubby perennial, which forms rounded
clumps. It grows on coastal sands and flowers between March and July.
Global Distribution
This variety of the species is endemic to Gibraltar.
Local Distribution
The species is restricted to the Great Sand Slopes of the east side of the Rock, all the way from the
northern extremity at Devil’s Tower Road, to the southern extremity above Sandy Bay, and also above and
below Sir Herbert Miles Road. It is not found elsewhere in the wild.
POPULATION TREND: Increasing.
Threats
At present the species is thriving throughout its habitat, especially on the areas exposed by the removal
of the water catchment sheeting. The threat to the species would arise if the habitat, or parts of it, were to be
opened up for development, or if it were to be quarried for sand. At present the only threat comes from the
spread of the introduced, invasive species Acacia cyclops and Carpobrotus edulis x acinaciformis. Fire is a
serious consideration, for in the summer of 2005 most of the Gibraltar Government’s (northern) area of the
Sand Slopes was burnt. Monitoring and regular surveys of the Great Sand Slope for the spread of invasives
and the status of this plant should take place. Fire hazards should be pointed out as part of these surveys.
Action
The habitat in which this species grows must be allowed to remain in its natural state, and set up as a
nature conservation area under the provisions of the Nature Protection Ordinance. This will protect not only
this species, but all of the species of plants and animals that make up this unique community. A programme
of removal of invasive species would go a long way in safeguarding the future of the habitat, and of the
native species found there. Monitoring and regular surveys of the Great Sand Slope, to assess the damage
done by the fire and the extent of the encroachment of invasive species is required to formulate a viable
conservation management plan for this site. The designation of the Great Sand Slopes as within the candidate
Special Area of Conservation (cSAC) will benefit the welfare of the species.
Ex-situ conservation should be encouraged through cultivation and banking of seed in the Gibraltar
Botanic Gardens. The species grows well in the sandy soils of the Gardens.
Class: Angiospermae Order: Plumbaginales Family: Plumbaginaceae
GIBRALTAR SEA LAVENDER
Limonium emarginatum
Figure 18: Gibraltar Sea Lavender Limonium emarginatum. (L. Linares)

General Description
A hairless perennial flowering mainly between March and September. This species grows on cliffs and
rocky ground in close proximity to the sea.
Global Distribution
Endemic to the Strait of Gibraltar, where it is mainly found on the Rock, with scattered populations
along the Tarifa area of the Cadiz coastline and on the opposite side of the Strait in Morocco and Ceuta.
Local Distribution
Found mainly along the coastal cliffs around the Europa Point area with an important concentration on
Europa Foreshore where the plants form large dense cushions. The plant is also distributed along the east
sea cliffs from Europa Point to Catalan Bay and along the west to Rosia Bay. Never found far from the sea,
where they are washed by sea spray, except for some plants found on the cliffs in the vicinity of Martin’s
Cave on Mediterranean Steps, some 200m above sea level.
POPULATION TREND: Stable.
Threat
Europa Foreshore has in the past been selected for development proposals, although the area where
the plants grow is not suited for this since it is exposed to strong easterly winds and frequently washed in
sea spray. The other plants found scattered along the cliffs on the eastern side are not under threat since
their inaccessibility and location affords them protection, except where cliff works are proposed.
Much of the area in the south district where the species is found, in particular areas adjacent to cliff habitat
and the Europa Foreshore, is an invasive hot spot. Here numerous invasive species of plant compete
for resources and space with the Sea Lavender, and should be removed (see chapters 4 and 6.
Residents at Europa Foreshore have released pet rabbits that have become feral and which could
graze on this plant.
Action
The main colony of plants on Europa Foreshore requires protection as the species forms a dense community
at the eastern end of this habitat, the like of which is not found elsewhere. This protection should
be in the form of a nature conservation area on the Europa Foreshore, since there are a number of other
interesting plant species that are only found in this area.
The eradication of the feral rabbits on the Europa Foreshore is a priority if the community of plant
species found in this interesting habitat is to survive.
Ex-situ conservation should be encouraged through cultivation and banking of seed in the Gibraltar
Botanic Gardens. Some specimens grow in the Gardens, although germination success is poor.
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Class: Angiospermae Order: Rhoedales Family: Cruciferae
GIBRALTAR CANDYTUFT
Iberis gibraltarica
Figure 19: Gibraltar Candytuft Iberis gibraltarica.
General Description
The Gibraltar candytuft is a robust, woody-based, branched perennial, which grows from limestone
crevices on the cliffs and screes. It flowers from March to June.
Global Distribution
A native of Morocco and Gibraltar, with Gibraltar being the only European station for the species.
Local Distribution
Found on cliffs ranging from the North Face of the Rock, along the cliffs above the east side sand
slopes, and on to the cliffs around Europa Point and Windmill Hill round to the west up to the easternmost
cliff of the North Gorge area. It is also found on stony ground elsewhere, such as the south-facing slopes
from O’Hara’s Battery to Windmill Hill Flats and on rocky outcrops on the Upper Rock. Scattered plants
may be seen elsewhere including the east side sand slopes. Occasionally by the sea.
POPULATION TREND: Stable.
Threats
So long as the cliff habitats are not interfered with, the species is under little threat. However, cliff stabilisation
programmes do pose a threat. Encroachment of shrub vegetation in some areas may reduce
local populations on outcrops and screes away from cliffs.
Action
Cliff stabilisation must be avoided. Any that is absolutely inevitable due to current safety needs should
be carried out with care and attention to species of plants and animals found on the cliffs. Concreting must
be avoided.
Woody vegetation control on the Upper Rock should be carried out if isolated populations are threatened.
Ex-situ conservation should be encouraged through cultivation and banking of seed in the Gibraltar
Botanic Gardens, where there is a thriving population.

Class: Angiospermae Order: Rosales Family: Saxifragaceae
GIBRALTAR SAXIFRAGE
Saxifraga globulifera subsp. gibraltarica
Figure 20: Gibraltar Saxifrage Saxifraga globulifera subsp. gibraltarica (L. Linares).
General Description
The Gibraltar Saxifrage is a herbaceous perennial that grows in shady limestone crevices and stone
walls and flowers between April and June.
Global Distribution
This subspecies is endemic to Gibraltar.
POPULATION TREND: Stable but vulnerable.
Local Distribution
The largest population of this species can be found at Rock Gun, growing on old, stone walls. Some
are also found growing from limestone crevices in the northern part of the disused catchment area between
Rock Gun and above Green’s Lodge Road. Very few can also be found near the top of the road leading to
the Upper Galleries. Here they grow from limestone crevices along the east side of the road. Another stand
can be found near the top of Mediterranean Steps, growing again from limestone crevices. Scattered
plants were once discovered among rocks along Bruce’s Farm firebreak and on the Lower Slopes of the
Upper Rock. However recent searches have failed to find them.
Threats
The threat to this species comes from two sources: the activity of Barbary macaques in both the Rock
Gun and O’Hara’s Battery areas where they cause disturbance to the habitat and the plants themselves,
and from the deliberate clearing of the roadsides and walls at the Upper Galleries. The latter has already
occurred repeatedly, with a large number of plants scraped away. This could also be a threat to the population
at Rock Gun if this area was targeted for development.
Action
Implementation of the recommendations in Perez & Bensusan (2005) to establish a biological reserve
within the area denominated as Rock Gun and Middle Hill would protect the habitat of the species. The
present location of the main stands should be pointed out to cleaning contractors of the Upper Rock Nature
Reserve, so that there is no interference with the plants or their habitats. Seeds should be collected, and
sown in areas identified as suitable. These should also be grown at the Gibraltar Botanic Gardens and then
relocated to suitable sites both inside the Gardens and on the Upper Rock. Members of the Caves & Cliffs
Section of GONHS could be instrumental in introducing plants to more inaccessible sites.
Ex-situ conservation should be encouraged through cultivation and banking of seed in the Gibraltar
Botanic Gardens, although this has been tried without success.
This subspecies should be included under Annex II of the Habitats Directive 92/43/EEC.
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Class: Angiospermae Order: Laurales Family: Lauraceae
SWEET BAY OR LAUREL
Laurus nobilis
Figure 21: Sweet Bay Laurus nobilis. (L. Linares).
General Description
The Sweet Bay is a tree or large shrub with aromatic, evergreen leaves and shiny grey bark. Clusters
of small yellow flowers are produced in spring, followed, on the female plants, by shiny black or purple
berries about 1.3 cm long.
Global Distribution
A native species of the Southern Mediterranean, also grown in other countries for its aromatic leaves
which are used for culinary purposes. The plant is native in the wetter areas of the Parque Natural de los
Alcornocales on the west side of the Bay of Gibraltar.
Local Distribution
The Sweet Bay is mainly restricted to the South District where it has survived in gardens, but is also
found in the lower boundaries of the southern end of the Upper Rock Nature Reserve. There is also a
stronghold of this species in the North Gorge. Isolated pockets of the species – what is believed to be a
relict population – can be found on the cliffs below Rock Gun and around the St. Michael’s Cave area.
POPULATION TREND: Increasing.
Threats
Areas in the South District are under development pressure. The North Gorge site was due for development
(Highcliffe House), but the plans were changed at the insistence of the Development & Planning
Commission following a site assessment and recommendations by GONHS.
Action
This species and the habitat associated with it, classified as habitat code 5230 as ‘Matorral with Laurus
nobilis’ is considered a priority habitat under Annex I of the Habitats Directive 92/43/EEC.
The main stronghold of the species, in the Mount Gardens and North Gorge should be protected as this
is a Priority Habitat type under the Habitats Directive. These two areas hold most of the mature trees that
escaped in the deforestation 1700s, while the North Gorge site (below Windmill Hill Road) holds a large
number of young trees in what is a naturally regenerating woodland. This area should be given nature conservation
area status under the Nature Protection Ordinance.
Evidence of the relict stands on inaccessible cliffs around Rock Gun point to the Bay Laurel as one of
the main arboreal species found in Gibraltar before humans wiped out the natural vegetation. Monitoring
of the spread of this species on the Rock will bolster efforts for the conservation of this species.

Class: Angiospermae Order: Contortae Family: Oleaceae
NARROW-LEAVED ASH
Fraxinus angustifolia
Figure 22: The Narrow-leaved Ash Fraxinus angustifolia. (L. Linares).
General Description
The Narrow-leaved Ash is an upright deciduous tree with a broadly oval crown sometimes reaching 10m
in height. The trunk is smooth and brown on young trees but becomes grey with ridges and furrowed with
age. It flowers in early spring before the leaves sprout, with male maroon flower dense clusters and looser
green female flowers. The leaves are shiny, dark green above and lanceolate, 10-15cm long, serrated
and tapering. It grows best in damp soils.
Global Distribution
Native of North Africa and the Iberian Peninsula, the tree has been introduced to many countries with
similar Mediterranean climatic conditions.
Local Distribution
Found mainly within the gardens of the Mount and elsewhere in the south District. The species has
spread into the surrounding area with many young saplings along Engineer Road at the entrance to the
Upper Rock. Also well represented in the Sandpits area, south of the Botanic Gardens and present also in
the Gardens and the Trafalgar Cemetery where a particularly large specimen can be seen.
POPULATION TREND: Increasing.
Threats
The species is not under threat but due to its limited distribution could be adversely affected by the
development of its main strongholds.
Action
The remnants of the species in gardens points to the time when these areas remained as a refuge for
trees after the felling of combustible material on the Rock during the Great Siege and other sieges. This
species of tree is representative of farily moist Mediterranean woodland and it is probable that it flourished
on the lower parts of the Rock, including the area where the Town now stands, together with other native
species that were wiped out. It is therefore gratifying to see that the species is self seeding into the surrounding
area and would benefit from a recovery programme that would introduce the species into other
areas of Gibraltar.
Species Action Plans
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Class: Insecta Order: Coleoptera Family: Buprestidae
Buprestis (Yamina) sanguinea ssp. calpetana
Figure 23: Buprestis (Yamina) sanguinea ssp. calpetana, male (left) and female (right).
General Description
The larvae of this attractive jewel beetle feed on plants of the genus Ephedra. In Gibraltar, they are
found on Ephedra fragilis, the only representative of this genus on the Rock. Adults or imagos emerge no
earlier than mid-July, and are most easily encountered near their host plants during August. Larvae take
two years to develop into adults, during which time they feed within the stems of Ephedra. The presence
of larvae within their host plants does not seem to affect these plants in any way, since more numerous
emergences of imagos seem to occur on healthier specimens of Ephedra.
Buprestis sanguinea ssp. calpetana exhibits strong sexual dimorphism, an unusual trait amongst beetles.
Global Distribution
In Iberia, Buprestis sanguinea is widespread but very scattered. Originally known only from mountains
in Teruel in Aragon, it has now been recorded in other parts of Aragon, Cataluña, Madrid and Murcía, as
well as in Gibraltar (Perez & Bensusan 2006). The species, which was originally described from North
Africa, where it has been recorded from Morocco to Libya, has now been split into two subspecies; B. s.
iberica from Spanish populations and B. s. calpetana from Gibraltar (Verdugo et al., 2006)
Local Distribution
Buprestis sanguinea ssp. calpetana is endemic to Gibraltar where it is only found on its host plant
Ephedra fragilis. This plant is quite widespread in Gibraltar, where it grows mainly on cliffs and rocky
garigue habitats. So far, this beetle has only been located along Mediterranean Steps, at Governor’s
Cottage and Mediterranean Road, above Sandy Bay and on the Talus above Catalan Bay. It is likely however
that it occurs wherever numerous healthy examples of Ephedra fragilis grow.
POPULATION TREND: Stable.
Threat
As is most often the case with invertebrates, habitat destruction is the most serious threat to this
species. Since a large portion of the local distribution of this species falls with the Upper Rock Nature
Reserve or otherwise within the candidate SAC, its future seems secure locally. However, the recent spate
of cliff stabilisation work could threaten it in some key areas, since large and healthy populations of Ephedra
fragilis grow in cliff habitats.
Action
A reduction of cliff stabilisation measures would benefit not only this beetle, but also all fauna and flora
reliant on cliffs as their habitat.
Buprestis sanguinea ssp. calpetana could make an interesting subject for research projects, given that
very little is yet known about the species’ biology and that it has an interesting distribution. As such, a blanket
ban on collection of individuals is not desirable. Rather, it should be protected under schedule 1 of the

1991 Nature Protection Ordinance (L/N 11 of 1991), with collection allowed only by serious researchers and
coleopterists under licence. Coleopterists collecting specimens should not be allowed to collect more than
five individuals a year, unless a specific research licence is granted.
The restricted global distribution and the fact that the Gibraltar taxon is classified as a separate subspecies
(Verdugo et al., 2006.) requires that this beetle be included under Schedule I of the Nature
Protection Ordinance (L/N 11 of 1991). Ephedra fragilis should be removed from Schedule 2 of the Nature
Protection Ordinance which, as this is a reverse-list, would afford it protection.
Class: Arachnida Order: Aranei Family: Hexathelidae
GIBRALTAR FUNNEL-WEB SPIDER
Macrothele calpeiana
Figure 24: Gibraltar Funnel-web Spider, Macrothele calpeiana. (K. Bensusan).
General Description
The Gibraltar Funnel-web Spider, Macrothele calpeiana occurs in damp shady localities, and is mainly
nocturnal in its habits. It lives within a burrow under rocks, on tree trunks and in old walls. The burrow is
lined with a simple web funnel that is anchored to surrounding objects. The females can be found with eggsacs
and spiderlings from the end of July onwards, and its diet includes isopods and hymenoptera,
coleoptera and other insects (Gallon, 1994).
Global Distribution
Formerly thought to be restricted to a small area of southern Spain and Gibraltar, its range is now known
to cover much of southern Andalucía and new data points to isolated populations elsewhere including as
far north as southern Extremadura (Díaz Rodríguez & García Villanueva, 2000)
Local Distribution
Found mainly in damp wooded areas in gardens and the Nature Reserve, and occasionally in caves
and buildings. Large populations are also known from the East Side.
POPULATION TREND: Stable.
Threats
The spider is well distributed around Gibraltar and its survival as a local species is not under threat.
Action
This species is protected by the Nature Protection Ordinance 1991 and listed under Annex II of the
Habitats Directive 92/43 EEC (Helsdingen & Decae, 1992), which requires designation of its habitat as a
Special Area of Conservation, and therefore its prime habitats should be conserved at all costs. In this
respect, much of its habitat is being considered at the present time for designation. It is important however
to note that some of the prime sites for this species fall outside of the candidate SAC, and local legislation
must be implemented to ensure that the future of the species in Gibraltar is safeguarded by affording
protected status as nature conservation areas under the Nature Protection Ordinance to such sites.
Species Action Plans
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Class: Gastropoda Order: Architaenioglossa Family: Aciculidae
Acicula norrisi
Figure 25: Acicula norrisi Gittenberger and Boeters, 1977.
Actual height 2.9mm (drawing by Salli Menez).
General Description
Shells have been found in soil and leaf litter samples adjacent to limestone rocks and cliffs. The species
has not yet been collected live, but very fresh shells with remnants of animals inside, indicate the species
is extant. These fresh shells are generally found under rocks (approximately to 0.5m below soil level) in
scree and garigue habitats. (Menez in prep).
Global Distribution
Endemic to Gibraltar.
Local Distribution
Found in Windmill Hill Flats, Mediterranean Steps, the slopes around Little Bay and the Europa
Foreshore.
Threat
Habitat destruction in parts of its range (in particular areas on the lower levels of the Upper Rock and
near Windmill Hill Flats).
Action
The verification of live populations and their study is a priority.
Once these requirements have been established the possibility of translocation to new localities, with a
view to increase the distribution of the species locally, should be investigated.
The maintenance of habitats where the species occurs and prevention of development in these habitats
(that are also important for many other taxa).
Although the species is afforded local protection under the Nature Protection Ordinance 1991 (L/N
1991), and the Endangered Species (Import and Export) Ordinance 1990, the species does not have international
protection. Therefore this endemic species should be included under Annex II of the Habitats
Directive 92/43/EEC and in the World Conservation Union’s ‘IUCN Red Data List of Threatened Species’.
Most of the locations where the species is found are included within the habitat action plans for the
South District and the Upper Rock Nature Reserve. Windmill Hill and the Upper Rock have been included
as a candidate Special Area of Conservation cSAC, and this should guarantee the welfare of the species.

Class: Gastropoda Order: Pulmonata Family: Trissexodontidae
OSTEOPHORA CALPEANA
Figure 26: Oestophora calpeana (Morelet, 1854). (drawing by Salli Menez).
General Description
Never abundant, typical densities in sampled areas of 400m 2 are 0.1-1/m 2 (Menez, in prep.). Usually
found under rocks, logs and other types of shelter in steppe, garigue and maquis habitats.
Global Distribution
This species has a restricted range and is known only from the area of the Strait of Gibraltar, with
records from Tangier and Ceuta in North Africa, and from Gibraltar, its type locality.
Local Distribution
Found on the Great Sand Slopes and Talus Slopes, the Upper Rock Nature Reserve and Lower Slopes,
Windmill Hill Flats, the slopes around Little Bay and the Europa Foreshore.
Threats
Habitat destruction in parts of its range (in particular areas on the lower levels of the Upper Rock and
near Windmill Hill Flats).
Action
Most of the locations where the species is found are included in specific Habitat Action Plans and
Windmill Hill and the Upper Rock have been included as a candidate Special Area of Conservation (cSAC)
that should guarantee the welfare of the species.
Although the species is afforded local protection under the Nature Protection Ordinance 1991 (L/N
1991), and the Endangered Species (Import and Export) Ordinance 1990, it does not enjoy international
protection. It would be desirable, due to its restricted global distribution, for the species to be included
under Annex II of the Habitats Directive 92/43/EEC and in the World Conservation Union’s ‘IUCN Red Data
List of Threatened Species’.
Species Action Plans
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Class: Gastropoda Order: Archaeogastropoda Family: Patellidea
MEDITERRANEAN RIBBED LIMPET
Patella ferruginea
Figure 27: Mediterranean Ribbed Limpet Patella ferruginea. (A. Yome)
General Description
A large limpet measuring up to 10cm at its widest, with strongly ribbed furrows. The species lives on
rocky substrates above sea-level on the upper mesolittoral zone. Normally found on natural rocky shores.
In one location near Gibraltar, Ceuta harbour, it has recently been found to be more abundant on artificial
harbour stones than on natural rocky substrate (Guerra Garcia et. al. 2003). This may be due to the fact
that there is a strong current flow in that harbour, as most harbours in fact have a high level of pollution, not
beneficial to the species.
Global distribution
Endemic species of the Western Mediterranean sea. Found mainly along the Iberian and North-west
African Mediterranean coastline with a small population in Sardinia.
Local distribution
Scarce along the rocky shoreline of Gibraltar with a recently discovered population on the western end
of the runway (D. Fa pers.comm.)
POPULATION TREND: Increasing.
Threats
The main threat to this species, which lives within the inter-tidal zone, comes from pollution. The
increase in bunkering activities in the Bay together with other industries, in particular the Oil Refinery, poses
a potential oil pollution problem that could seriously affect the well-being of the species in Gibraltar.
Development of our natural shoreline and reclamation projects has seriously undermined the natural habitat
of the species. Some of these projects have severely affected the current flows, particularly within the
Gibraltar Harbour, fundamental for the survival of the species.
Action
Legal Status: The species is the most endangered marine invertebrate in the Western Mediterranean
and as such is Included in the Annex II of the Bern Convention, Annex II of the Barcelona Convention;
‘Convention for the protection of the Mediterranean Sea against pollution’ and Annex IV of the Habitats
Directive 92/43 EEC under ‘Animals and Plant Species of Community Interest in need of strict Protection’.
In Gibraltar it is afforded protection under the Nature Protection Ordinance (L/N 1991), and in Schedule
I of the Endangered Species Ordinance (1990-54).
The recently discovered population of this species on the western end of the runway constitutes the
richest and largest concentration of the species in the Iberian Peninsula (D. Fa pers. comm.). The site is
composed of concrete blocks that were placed there to protect the runway from erosion that have only been
there less than fifteen years. It is therefore a recent colonisation and augers well for the future as this type
of shoreline protection may provide an alternative habitat for this species. However, this should not be
viewed as justification for the destruction of natural shores, as colonisation is by no means certain, and will
depend on many other conditions, including current flow. Neither does this mean that artificial substrates
are more suitable for the species. The species will therefore need continual monitoring, population surveys
and ongoing research to provide the optimum conditions for its welfare and survival in Gibraltar.

6. Alien, Invasive & Pest Species

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6. Alien, Invasive & Pest Species
Alien, Invasive & Pest Species
Alien species are species that have been introduced, either intentionally or accidentally, in habitats
where they do not form part of the native wildlife. Many exotic plant species thrive in gardens and urban
green areas, but in many cases have to be maintained artificially in order for them to survive. Most of
these plants cannot survive in the wild. Similarly, many species of exotic animals can be found in nature
reserves, wildlife parks and zoos, and many are kept as household pets. Most are dependent on our attention
for their survival and could not continue to exist in the wild.
There are exceptions among some species that, not only survive, but invade new habitats and outcompete
the indigenous species to establish themselves as one of the dominant species in their new environment.
These are termed ‘invasive’ or ‘alien’ species, and are generally considered second only to habitat
loss as the biggest threat to biodiversity.
The rapid increase in global trade, travel, tourism and exchange in goods this century has boosted the
cases of biological invasions worldwide, and continues to be a major threat to biodiversity. The impact
caused by invasive alien species includes not only the irreversible damage done to native species and their
ecosystems, but also on the management costs required to control, mitigate and rectify the problem.
It is imperative that there be a mechanism to address the impact of alien species, primarily through
sound legislation and enforcement, and clear guidelines that provide instructions for control, eradication,
and mitigation.
The Gibraltar Government through the Ministry for the Environment need to establish a programme for
the control and eradication of invasive species of flora. This should include mitigation measures with a
restoration and improvement programme for all sites that are affected by invasive species. Several factors
need to be taken into consideration, amongst which are:
• Identify the scale and size of the problem.
• Establish a means of control through biological, chemical and/or manual methods.
• Identify the manpower required for the establishment of a works team.
• Ensure the removal of the species before these go to seed.
• Identify a suitable disposal site and method that will not prejudice other areas.
• Conduct a habitat restoration programme.
• Follow up with a monitoring programme of all areas affected.
These points will need to be applied to all invasive species of flora.
Local goals to address the invasive and pest species problem.
• Evaluate risks associated with the introduction and spread of invasive species.
• Identify, monitor and exclude pathways involved in the introduction of invasive species.
• Promote information for reducing the risk of invasive species introduction to Gibraltar.
• Detect early and respond rapidly to populations of new invasive species in a cost effective and environmentally
sound manner.
• Provide leadership to other agencies to resolve problems associated with invasive and pest species.
• Promote public education on invasive and pest species and how to address them.
• Document, evaluate, and monitor the impacts of invasive and pest species on the economy, environment
and human health.
• Legislate against the introduction of alien species that are known to be problematic, even as pets or
household plants.
Public awareness campaign for the reduction of invasive species.
• Verify that the plants you are buying for plant pots or gardens are not invasive.
• Replace invasive plants in your garden with non-invasive alternatives.
• Ask your suppliers for help in identifying invasive plants.
• Do not import live flora and fauna when travelling.
• Fruits and vegetables, plants, insects and animals can themselves carry pests or become invasive.
• Do not release aquarium fish and plants, live bait or other exotic animals into the wild.
• Return unwanted pets to the pet shop.
• Become a volunteer with GONHS or the Botanic Gardens to help remove invasive species.
• Help educate others about the invasive and pest species threat.
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Alien Plant Species in Gibraltar.
Gibraltar has not escaped the worldwide phenomenon of biological introductions and invasions.
Indeed, if we look closely at our most charismatic species, the Barbary macaque was introduced in recent
history, by either the Romans or Moors. There is no evidence in the fossil record of this animal being present
on the Rock after the last glaciation. Through colonisation by different cultures many species of wildlife
were introduced into Europe from Asia and Africa. The Olive tree Olea europea, is believed to have come
from the Eastern Mediterranean, and is now established as a key species in Iberia and is the dominant plant
species in Gibraltar.
Colonisation by the British in 1704 and the establishment of trade links with the British Empire outposts
resulted in the arrival of innumerable exotic species en route from the colonies to the British Isles (Cortes
& Abrines 1994). Some of these species were eventually incorporated into the gardens of military
dwellings in Gibraltar, where the climate was favourable. Among them were many species from South
Africa, Australia and South America, and many of them still survive in the wild today. Most were harmless,
colourful exotics, but a few species that were introduced into Gibraltar have proved to be serious invasives,
whilst others are potential invasives. A list of all alien species of flora, with their country or region of origin,
can be found in Table 1.
Table 1: Alien species of flora found in Gibraltar.
Common Name Latin Name Country of Origin
Blue-Leaved wattle Acacia saligna West Australia
Red-eyed acacia Acacia cyclops Australia
Swamp wattle Acacia retinoides South Australia
Tree houseleek Aeonium arboreum Morocco
Pink houseleek Aeonium haworthii Canary Islands
Century plant Agave americana Mexico
Green century plant Agave ghiesbreghtii S Mexico; Guatemala
Tree of heaven Ailanthus altissima China
Cape wattle; Swamp wattle Paraserianthes lophantha S & W Australia
Soapy aloe Aloe maculata South Africa
Tree aloe Aloe arborescens South Africa
Spreading amaranth Amaranthus blitoides America
Narrow-leaved amaranth Amaranthus muricatus South America
Cape weed Arctotheca calendula South Africa
Giant reed; Cane Arundo donax Asia (probably)
Bridal creeper Asparagus asparagoides South Africa
Squamate aster Symphyotrichum squamatum South America
Golden bur-marigold Bidens aurea Central America
Lesser bur-marigold Bidens pilosa South America
Rescue brome Bromus unioloides South America
Hottentot fig Carpobrotus edulis x acinaciformis South Africa
Cestrum Cestrum parqui South America
Chasmanthe Chasmanthe floribunda subsp. floribunda South Africa
White horseweed Erigeron bonariensis South America
Horseweed Erigeron canadensis South America
Canadian fleabane Erigeron sumatrensis North America
Lesser swine-cress Coronopus didymus South America
Ivy-leaved toadflax Cymbalaria muralis subsp. muralis Sicily, Yugoslavia, Switzerland
Greater thorn apple Datura innoxia Central America
Thorn apple Datura stramonium Central & S America
Disphyma; Round-leaved Pigface Disphyma crassifolium South Africa
Dragon tree Dracaena draco subsp. ajgal Canary Is. & Morocco
Red gum Eucalyptus camaldulensis Australia
Blue gum Eucalyptus globulus Tasmania
White snakeroot; Snow thoroughwort Eupatorium rugosum North America
Freesia Freesia refracta South Africa
Bristly-fruited silkweed Gomphocarpus fruticosus South Africa
White iris Iris albicans Arabia
Mother of thousands Kalanchoe tubiflorum Madagascar
Four o’clock plant; Marvel of Peru Mirabilis jalapa Tropical America & Mexico
Myoporum; Waterbush Myoporum tenuifolium Australia
Shrub tobacco Nicotiana glauca South America

Common Name Latin Name Country of Origin
Large-flowered evening primrose Oenothera erythrosepala America
Pink evening primrose Oenothera rosea South America
Prickly pear; Barbary fig Opuntia ficus-indica Tropical America
Prostrate cactus Opuntia vulgaris Tropical America
Pink oxalis Oxalis articulata South America
Procumbent yellow sorrel Oxalis corniculata North America
Bermuda buttercup ; Cape sorrel Oxalis pes-caprae South Africa
Greater millet grass Paspalum dilatatum Brazil & Argentina
Millet grass Paspalum paspalodes subsp. paspalodes Tropical America
Pelargonium Pelargonium inquinans South Africa
Canary palm Phoenix canariensis Canary Islands
Virginian or American pokeweed Phytolacca americana Central & North America
Ombu Phytolacca dioica South America
Greater plantain Plantago major subsp. major Eurasia & N America
Castor oil plant Ricinus communis Tropical Africa
Californian pepper tree; Peruvian mastic tree Schinus molle South America
Climbing groundsel Senecio angulatus South Africa
Apple of Sodom Solanum sodomeum South Africa
Nasturtium Tropaeolum majus South America
Spiny cocklebur Xanthium spinosum South America
Cocklebur; Rough cocklebur Xanthium strumarium subsp. cavanillesii North America
Alien, Invasive & Pest Species
The majority of these alien plant species are located within gardens and urban green areas and do not
pose a threat to the native species of flora. Nevertheless, some species have established themselves in
the wild, with varying degrees of success, and some are invasive and are causing serious damage to the
natural environment. These species require an action plan that will address their control and removal, and
tackle the restoration of affected habitats.
Table 2: Alien species of concern that have become established in the wild.
Species Threat Species Threat
Acacia cyclops vp Chasmanthe floribunda vp
Acacia saligna p Disphyma crassifolium p
Aeonium haworthii p Lantana camara pp
Aeonium arboreum p Nicotiana glauca p
Agave americana p Opuntia ficus-indica vp
Agave ghiesbreghtii p Oxalis pes-caprae p
Ailanthus altissima vp Paraserianthes lophantha vp
Aloe arborescens pp Pennisetum clandestinum vp
Aloe maculata pp Senecio angulatus vp
Asparagus asparagoides pp Tropaeolum majus p
Carpobrotus acinaciformis x edulis vp Yucca elephantipes pp
vp: very problematic; p: problematic; pp: potential problematic
Table 2 lists those species of concern that have become established outside garden areas. Among
these are several that are notorious invasive plant species. Many species in the main table do not pose a
threat to the natural environment, although they could become a potential threat in the future. Nevertheless
many of these species have become established within Gibraltar and compete with the native flora. They
should therefore be removed.
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Alien Invasive Flora
The threat posed by many of the alien invasive species of flora that have become established in the wild
calls for the preparation of alien species action plans that will address concerns, and present solutions and
recommendations. The criteria used in selecting the species are based on several factors. Amongst these
are species already causing serious damage and spreading significantly (classified as very problematic,
‘vp’), species that are less damaging and threatening but also capable of spreading (problematic, ‘p’) and
those species that are serious invasives in other countries and could become a serious concern in the
future, but are not at present established in Gibraltar (potentially problematic ‘pp’).
The action plans for alien species provide a short description and photograph of the plant in question,
together with global distribution and a detailed description of the local distribution. Where the species has
an extensive local distribution, a map shows the location of species presence within the red dots covering
10m 2 . A summary of the details of the threat and damage the species is causing locally is covered extensively
together with remedial action, recommendations and where possible detailed methods for the control
and/or eradication of the species. These include manual, physical, biological and chemical control
methods. The invasive species problem within the Nature Reserve should be tackled by the works team
recommended in the chapter on introduced flora in ‘Upper Rock Nature Reserve. A Management and Action
Plan’ (Perez & Bensusan, 2005). This works team is already clearing many of the paths and could also be
employed to tackle the invasive flora elsewhere in Gibraltar.
A useful addition to the plan is a list of publications dealing with the invasive species problem in other
countries. These could prove helpful in the preparation of alien invasive species programmes.
Alien Invasive Species of Flora for which action plans have been prepared:
• Rooikrans Acacia cyclops
• Orange or Golden Wreath Wattle Acacia saligna
• Pinwheel & Tree Houseleek Aeonium haworthii & A. arboreum
• Century Plants Agave americana & A. ghiesbreghtii
• Tree of Heaven Ailanthus altissima
• Tree Aloe & Soapy Aloe Aloe arborescens & A. maculata
• Hottentot Fig Carpobrotus edulis x acinaciformis
• African Cornflag Chasmanthe floribunda
• Purple Dewplant Disphyma crassifolium
• Bush Lantana or Shrub Verbena Lantana camara
• Shrub Tobacco Nicotiana glauca
• Prickly Pear Opuntia ficus-indica
• Bermuda Buttercup Oxalis pes-caprae
• Cape Wattle Paraserianthes lophantha
• Kikuyu Grass Pennisetum clandestinum
• Cape Ivy Senecio angulatus
• Nasturtium Tropaeolum majus
• Spineless Yucca Yucca elephantipes

Alien Species Action Plan
Class: Magnoliopsida Order: Fabales Family: Mimosaceae
ROOIKRANS
Acacia cyclops
Figure 1: The Rooikrans Acacia cyclops, and open seed-pods.
Alien, Invasive & Pest Species
Description & Biology
A dense, slow growing evergreen bushy shrub or small tree from 3 to 8 metres tall, often multi-stemmed
with a rounded crown. The foliage is comprised of light green phylodes growing in a downward vertical
position and is resistant to sand blast and salt spray. Pods mature in the summer, but are not shed and
remain on the tree. The seeds remain viable in the soil for many years (Duke, 1983).
Global Distribution
A native of South-western Australia where it mainly grows on costal dunes. Introduced in many other
parts of the world, including South Africa, where it was used
for stabilisation on sand and sandstone, but is spreading into
coastal bush and heathland.
Local Distribution
Found mainly on the northern end of the Great Sand
Slopes above the Caleta Hotel, in an area that was not
required for the water catchment, and where it was planted
for sand stabilisation, together with a large number of palms
of the species Phoenix canariensis, and some Acacia
saligna. From there it is quickly spreading to the newly
restored habitat on the Great Sand Slopes.
Figure 2: Distribution of Acacia cyclops on
the eastern side of the Rock. The main concentration
is the original site of the plantation.
Note the spread of the species on the Great
Sand Slopes since the removal of the water
catchments.
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Threat
A very dangerous invasive species, Acacia cyclops is an extremely weedy species. Once established,
it is difficult to remove or replace. There is little natural vegetation cover beneath an Acacia cyclops thicket.
It has no natural enemies in Gibraltar and the Acacia thicket is devoid of any animal or plant life, creating
a veritable desert for native wildlife.
The Acacia stand was restricted to this area for many years and was incapable of spreading to the nearby
talus slope. Nevertheless with the removal of the water catchments, a huge area of suitable habitat has
now been opened up for colonisation. Within the space of a few years this invasive has quickly spread into
the adjacent area and is threatening the biodiversity of this newly restored habitat. Most of the new plants
can be found in a narrow band along the lower reaches of the slope where the seeds have spread.
Surprisingly, some plants can be found higher up the slope and the method of seed dispersal to these areas
is unknown.
This invasive is one of the most serious threats to biodiversity in Gibraltar and is threatening the unique
habitat of the Great Sand Slopes, a habitat that was recently restored through collaboration of the Gibraltar
Government and the MoD, with GONHS and the Botanic Gardens, who seeded the slopes with native flora.
Action
Urgent action is required within the next few years for the control and eradication of the species from
Gibraltar. If this does not happen soon, the welfare of the Great Sand Slopes, a candidate Special Area of
Conservation (cSAC) will be compromised, and the costs involved in remedying the problem at a later stage
will only escalate.
A biological control agent, the species of beetle called the ‘Rooikrans Seed Weevil’ (Melanterius servulus)
is used for the control of this species in South Africa. It was used for the first time in 1994 and is confined
to its host plant species. The adult feeds on the flowers and developing seeds. The female feeds on
the walls of the developing pods and lays its eggs on the seeds, where the larvae feed on the seed tissue
(ARC-PPRI).
Given the isolation of this invasive in Gibraltar and the host dependency of the biocontrol agent, it may
be possible to use this species as a control method to arrest the invasive plants’ dispersal until such time
as the A. cyclops plantation is finally removed.
In lieu of the biological control agent, manual control through the use of herbicides is preferable. The
dead material would later need to be removed and the area re-seeded with local species.
Further Reading
• Hall, A.V. and Boucher, C. (1977) The threat posed by alien weeds to the Cape flora. In Proceedings
of the Second National Weeds Conference of South Africa Stellenbosch, 2-4 February, pp. 35 -
45. A. A. Balkema, Cape Town.
• Macdonald, I.A.W., Kruger, F.J. and Ferrar, A.A. (eds.) (1986) The ecology and management of biological
invasions in Southern Africa, especially chapters by G. Shaughnessy, "A case study of
some woody plant introductions to the Cape Town area", pp.37 - 43 ; Macdonald, I.A.W. and
Richardson, D.M., "Alien species in terrestrial ecosystems of the fynbos biome", pp. 77 - 91 : and
Macdonald, I.A.W., Powrie F.J. and Siegfried, W.R., "The differential invasion of southern Africa’s
biomes and ecosystems by alien plant and animals," pp. 209 - 225. Oxford University Press,
Cape Town.
• Macdonald, I.A.W. Clark, D.L. and Taylor, H.C. (1989) The history and effects of alien plant control
in the Cape of Good Hope Nature Reserve, 1941 – 1978. South African Journal of Botany, 55:
56 - 75.

Class: Magnoliopsida Order: Fabales Family: Mimosaceae
ORANGE OR GOLDEN WREATH WATTLE
Acacia saligna
Figure 3: The Golden Wreath Wattle or Orange Wattle. Acacia saligna (L. Linares).
Alien, Invasive & Pest Species
Description & Biology
A large shrub or small tree growing up to height of 10 m, sometimes developing a spreading crown. The
bark is smooth and grey to red-brown on small branches. Young plants become dark grey and fissured with
age. Long branches are regularly covered in flowers that are composed of large golden balls in spring
(Michaelides, 1979). It occurs on poor acid or calcareous sands, and succeeds in the most dry and adverse
soil conditions.
Global Distribution
Native to the south-western corner of Western Australia, it has become naturalised in parts of Eastern
Australia. It is found mainly on sandy soils along the coastal plain. Used for eroded hillsides and wastelands
and for stabilizing drifting sands, it has been introduced in many parts of the world, including North
Africa, the Middle East, South Africa and for gully erosion in Uruguay.
Local Distribution
Found in very small numbers in the Acacia cyclops plantation on the Great Sand Slopes. It is also used
as an ornamental garden plant and can be seen in Casemates, Queensway and the Botanic Gardens. In
addition, some scattered individuals can be found throughout Gibraltar.
Threat
This is a species that was obviously introduced with Acacia cyclops for its sand binding qualities. The
plant spreads by means of suckers and is therefore a difficult species to eradicate. Roux and Middlemiss
(1973) state that caution is advised when using A. saligna, for in South Africa the species has become a
major weed and displaced indigenous species. It should therefore be treated as a potential invasive and,
together with A. cyclops, be removed.
Action
This species requires the total eradication from the Great Sand Slopes in conjunction with the action
programme mentioned under Acacia cyclops.
Older plants are susceptible to the gall rust, Uromycladium tepperianum and various gall-exploiting
insects, and in South Africa this gall rust is used as a biological control agent. A biocontrol agent for this
species is not required in Gibraltar, given the small size and distribution of the population of the species.
Ornamental plants may continue to be planted in landscaped gardens, although the species should not
be sited close to where the root system could spread the species into the wild. In this respect, the species
is totally unsuitable for planting in residential areas within the Nature Reserve or other areas close to wild
natural habitats.
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Class: Magnoliopsida Order: Saxifragales Family: Crassulaceae
PINWHEEL & TREE HOUSELEEK
Aeonium haworthii & A. arboreum
Figure 4: Tree Houseleek Aeonium arboreum in flower.
Description & Biology
A. arboreum is an erect, thick stemmed succulent shrub with a few branches, each bearing a rosette of
tightly packed leaves. The plant flowers in winter and early spring with an inflorescence of yellow flowers.
It is possible that the Gibraltar population of this species in fact consists of A. korneliuslemsii H.Y. Liu
(Lamb, 1994). A. haworthii has a thinner stem, with many branches bearing rosettes, and has a similar
flowering period with creamy pink flowers.
Global Distribution
Aeoniums originate from North Africa and the Canary Islands, but have also been introduced to the
Mediterranean region, south-western United States of America and Northern Australia, where it is listed
under the ‘National list of naturalised invasive and potentially invasive garden plants’.
Local Distribution
The Aeoniums can be found growing together primarily on the southern cliffs of Little Bay and Camp
Bay, round to the sea cliffs bordering Europa foreshore. A. arboreum is also found in large numbers around
the cliffs bordering Windmill Hill, on the east cliffs above Sandy Bay and extend their distribution right up to
O’Hara’s Battery where they can be found growing on the disused water catchments and adjacent cliffs. A
small stand of A. haworthii is located on the cliff leading down to Catalan Bay.
Threat
The Aeoniums are cliff dwelling species of plants that grow tightly bunched together, as can be seen at
Little Bay. They can therefore form dense mats on the cliffs that exclude native species. It is suspected that
the introduction of the species in Gibraltar begun at this location, where they found their way from the gardens
in the military dwellings on the cliff above. From here they have quickly spread to most of the cliffs in
the south of Gibraltar and have reached the highest point of the Rock. They pose a threat to many of the
native cliff growing species, in particular most of the rare species of plants that require special protection
such as Iberis gibraltarica and Limonium emarginatum.
Action
The Aeoniums are classified as ‘problematic’ (p). It is therefore essential that both species’ distributions
are closely monitored and their association with other native plants studied in depth to assess the potential
threat that these two species pose. It is possible that these species arrived naturally in Gibraltar from the
Canaries (Lamb, 1994) in which case they should be considered as a legitimate part of Gibraltar’s plant
community. Genetic studies should be carried out in order to attempt to ascertain the origins.
Aeoniums found growing in the Rock Gun and Middle Hill area and its surrounding cliffs should be
removed, as this is the stronghold of most of Gibraltar’s rare plants.
A specialist team of climbers will be required for the removal of the species from cliffs. Since this team
should be able to recognise important native species and problematic invasives, the GONHS Cliffs and
Caves section is the best-qualified and most appropriate body to tackle invasives and monitoring of species
on cliffs.

Class: Liliopsida Order: Asparagales Family: Agavaceae
CENTURY PLANTS
Agave americana & A. ghiesbreghtii
Figure 5: Century Plant Agave americana invading the Great Sand Slopes.
Alien, Invasive & Pest Species
Description & Biology
The Century plant Agave americana, is basically a basal rosette formed by very large grey-green leaves
up to 2 metres long and 30cm wide with marginal, curved spines and a viciously-tipped spine of over 4 cm.
The flower stalk grows in the late spring and summer up to a height of over 7 metres. It is branched and
grows yellow-green flowers that are pollinated by insects and birds. The seeds germinate on the branches
of the stalk, which eventually dies and collapses (sometimes uprooting the whole plant), but in so doing
propagating the new plants. Agave ghiesbreghtii is a less robust plant, with a flowering stem up to 5m tall.
The leaves are shorter and dark green and have smaller but more numerous marginal spines along the
edges.
Figure 6: An ‘invasive hot spot’,
Agave ghiesbreghtii, with
Carpobrotus acinaciformis x edulis,
and Acacia cyclops bushes in the
background growing on the Great
Sand Slopes.
Global Distribution
Both species occur naturally in arid areas of
eastern Mexico.
Local Distribution
Mainly found on the Great Sand Slopes, above
the Caleta Hotel and above the Both Worlds residential
area. A. americana is also found widely in
the Europa Point area, especially on the foreshore
where it is associated with a number of other introduced
species. Within the Upper Rock Nature
Reserve the plant is established on the firebreak at
the top of Charles V Wall, close to the Cable Car
Station and just below the Queen’s lookout.
Elsewhere the plant is grown as an ornamental garden
species within the Botanic Gardens and along
Rosia Road.
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Figure 7: Main distribution of Agave americana
on the east side of the Rock.
Figure 8: Main distribution of Agave americana
in the South District.
Threat
Agave americana and A. ghiesbreghtii are classified as ‘problematic’ (p). Planted on the sand slopes
along the water catchment drains, the plants are beginning to disperse widely, due mainly to the angle of
the slope that allows the new plantlets to roll down when the main stem collapses. This allows greater dispersal
than on level ground. This same problem is occurring with the few specimens found within the Upper
Rock Nature Reserve, which are also growing on slopes.
Plants growing around Europa Point are more tightly bunched and form large, impenetrable stands
where the huge rosettes of leaves exclude the sunlight and do not allow the growth of native plant species.
The problem is compounded on the Europa foreshore below where these plants grow in association with
other species of introduced flora that include Aloe maculata, Opuntia ficus-indica and Carpobrotus edulis x
acinaciformis.
Action
The removal of the species from the priority areas of the Great Sand Slopes and the Upper Rock Nature
Reserve, where the species is the main threat, is urgently required. This should be followed with the
removal of the species from the foreshore together with other individual plants around the Europa Point
area.
This is an easy species to tackle, mainly because of the few plants involved. The risk of accidental dispersal
during removal is also minimal.
Further Reading
• David M. Richardson. (2005) Diversity, distributions and conservation biogeography. Diversity &
Distributions, 11: 1-2.
• Swarbrick, J. T. (1997) Weeds of the Pacific Islands. Technical paper No. 209. South Pacific
Commission, Noumea, New Caledonia. 124 p.
• Waterhouse, D.F. (1997) The major invertebrate pests and weeds of agriculture and plantation
forestry in the Southern and Western Pacific. The Australian Centre for International Agricultural
Research, Canberra. p. 59.

Class: Magnoliopsida Order: Sapindales Family: Simaroubaceae
TREE OF HEAVEN
Ailanthus altissima
Figure 9: Tree of Heaven Ailanthus altissima (L. Linares).
Alien, Invasive & Pest Species
Description & Biology
Also known as Ailanthus, Chinese Sumac or stinking Sumac, this is a rapidly growing deciduous tree
that can reach a height of over 10 metres. A. altissima has smooth stems with a pale grey bark and reddish
brown twigs that are characteristic in the dormant season. It has large compound leaves that are composed
of 10-25 smaller leaflets lying alternate along the stem. Flowering in the late spring, the tree produces
papery twisted seeds in the autumn that are called samaras, and many remain on the tree for a long
period.
Global Distribution
The Tree of Heaven is native to Central China. It has been introduced to many countries worldwide
including forty-two states of the USA.
Local Distribution
The tree can be found behind Catalan Bay within the gardens of the abandoned dwelling called
‘Rockfall’, and in the old Quarry beside the entrance to Williams Way tunnel. Several specimens grow in
the Catalan Bay village and other isolated specimens can be seen near the Talus slope, Sandy Bay and
more worryingly on the Great Sand Slopes where they are beginning to spread. Also found in the Upper
Rock Nature Reserve in the old PSA Nursery, where there is a great thicket of small individuals and where
they are rapidly spreading. Established in the Mount gardens where there are several mature trees and a
thicket of young saplings. The species has spread into the lower reaches of the entrance to the Nature
Reserve and is capable of spreading further. Also found in gardens in the town area including the Trafalgar
Cemetery, where there is a majestic specimen and several saplings, and in the Botanic Gardens, where
they were a major problem. However, following an active control programme of felling, pruning and treatment
with weed killer, they are now restricted to the northern narrow stretch of garden, and at the southern
end where they have become established in the area around the Sandpits Lawn Tennis club.
Threat
A. altissima is an aggressive, rapidly growing tree that produces a great quantity of seeds (up to
325,000 on one tree) and is capable of overrunning the native vegetation. It also reproduces vegetatively
through a network of suckers in the root systems that can damage foundations and sewers. Once established,
the species forms an impenetrable thicket that prevents the growth of native species through the
production of toxins in the ground. The tree is capable of re-sprouting from cut stumps and remnants of
the root system.
The stands of trees on the Great Sand Slopes and the Upper Rock Nature Reserve require urgent attention,
for the species is rapidly spreading and could over-run the habitats in question. Individual specimens
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elsewhere should also be removed before they generate a new problem area.
Action
This species must be eliminated totally from Gibraltar. This must include ornamental garden specimens,
as these pose a threat via dispersal to natural habitats. Those planted in urban areas should also
be removed because of the potential damage that their root system can cause to structures.
A control, management and eradication programme for the removal of the species urgently needs to be
established. Great care is required in the removal of A. altissima, due to its high seed production and germination
and its vegetative reproduction. Cutting alone is counter-productive since Ailanthus responds by
producing innumerable root suckers.
Several control methods are available, but the most effective seems to be the use of herbicides, which
may be applied to the leaves, the bark and stump. Great care is required to avoid the application to native
species growing nearby. This will usually eliminate the plant growing above ground, but the root and sucker
system may remain active, and is capable of re-growing. Therefore continual monitoring, at least twice
a year, is required to ensure that the herbicide is applied to any re-growth. Constant application will eventually
weaken the tree and eliminate the problem, without physically having to tackle the root system.
Nevertheless removal of the entire plant including roots and fragments can be done when the soil is moist
(Pannil, 1995). In Gibraltar this may prove difficult, due to the rocky and stony nature of the underlying soil
in many areas.
Further Reading:
• Tennessee Exotic Pest Plant Council.(1996) Tree of Heaven. Tennessee Exotic Plant Management
Manual.
• The Nature Conservancy, California Regional Office (1988) Ailanthus altissima Element
Stewardship Abstract Report (prepared by Marc Hoshovsky). Arlington, Virginia.
• Virginia Department of Conservation and Recreation and Virginia Native Plant Society (1996)
Invasive Alien Plant Species of Virginia: Tree-of-Heaven (Ailanthus altissima (Miller) Swingle).
Class: Liliopsida Order: Asparagales Family: Aloaceae
TREE ALOE & SOAPY ALOE
Aloe arborescens & A. maculata
Figure 10: The Tree Aloe or Red-hot Poker Aloe arborescens.

Alien, Invasive & Pest Species
General Description
The Tree Aloe develops into a multi-headed shrub of 2-3 metres high with an attractive rosette of grey
green leaves, armed with conspicuous pale teeth. The large, colourful and characteristic inflorescences of
red flowers can be seen from December to late January. The flowers produce nectar that attracts birds and
insects. The Soapy Aloe’s leaves also develop in a stemless rosette but the leaves are dark green, sometimes
with a reddish tinge and has distinctive whitish spots. It flowers later than arborescens, with red inflorescence,
mainly in the spring.
Global Distribution
Both are native to southern Africa and also found in Malawi, Zimbabwe, Swaziland and Mozambique.
Introduced as an ornamental garden plant to many parts of the world, especially in countries with a
Mediterranean climate, where the species can grow in the wild.
Local Distribution
The Tree Aloe is distributed in the south of Gibraltar, in the
Europa Point area and around to Governor’s Cottage and the
Europa Advance. Other stands can be found at Sandy Bay, at
the southern end of Windmill Hill, at the base of the northern
Talus slope, around North Gorge and the Naval Hospital, and
within the Upper Rock Nature Reserve where there are stands on
the south-facing slopes below Mediterranean road, within the
gardens of Ince’s and Bruce’s farms, Tovey Cottage and the former
PSA Nursery.
Elsewhere the species has been planted as an ornamental
plant within the Botanic Gardens, the Mount Gardens, along
Rosia Road, along the perimeter of St. Paul’s church and around
Devil’s Tower Camp.
The Soapy Aloe is found along the Europa Foreshore, at Hole
in the Wall in Europa Advance, near the Cable Car top station
and scattered in small clumps along Camp Bay as well as within
the main gardens.
Figure 11: Main distribution of Aloe arborescens
in the south of Gibraltar.
Threat
The Tree Aloe forms a dense cover that excludes native species. Even around the periphery of these
clumps, native species do not grow particularly well and are shaded out. The Tree Aloe has until now
spread only vegetatively and very slowly. It has been unable
to set seed, being self-sterile, and has not therefore been a
major threat to the native species. However, soon after the
importation of other Tree Aloes into the Botanic Gardens in
1992, presumably of a different clone, it was discovered that
the Tree Aloes in the Garden were beginning to set seed.
This raises the potential threat of this species to potentially
problematic.
Figure 12: Tree Aloe with fruit in the
Alameda Botanic Gardens.
The Soapy Aloe is less prolific although they also shade
out the native species and could become a problem in the
future.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Figure 13: The Soapy Aloe Aloe saponaria. (L. Linares).
Action
At the moment the Tree Aloe does not pose a serious threat in Gibraltar. However, it would be wise
to eradicate some naturalised populations as these could become problematic in the future. Continual
monitoring of the species is required in order to assess the dangers of seed production and distribution, as
well as vegetative spread where the species is found.
Class: Magnoliopsida Order: Caryophyllales Family: Aizoaceae
HOTTENTOT FIG
Carpobrotus edulis x acinaciformis
Figure 14: Hottentot Fig Carpobrotus edulis x acinaciformis (L. Linares).
General Description
The Hottentot fig is a perennial, ground-hugging succulent that roots at the nodes and forms dense
deep mats that cover large areas. Its stems reach 2m in length and have bright green succulent leaves, 4-
8cm long, that are sometimes tinged with red. The species flowers in spring with large pink to violet flowers,
7-8.5cm in diameter that in some specimens are pale yellow. The Gibraltar plants were long thought
to be C. edulis, but are in fact a hybrid of C. edulis and C. acinaciformis that is unable to set seed.

Alien, Invasive & Pest Species
Global Distribution
Native to South Africa, the species has been introduced into other countries with similar climate for stabilisation
of sandy soils, and as an ornamental garden plant, especially in Spain, Portugal and France.
Local Distribution
Found in the Europa Point area, especially on scree slopes adjacent to sea cliffs, and at the base of the
Great Sand Slopes where they were planted for sand stabilisation, despite the fact that the species is
unsuitable for this on steep sites due to its shallow root system. Some other stands can be found at the
base of the northern talus slope and in the North Front aerial farm, with a few on the Upper Rock.
Figures 15 & 16: Main distribution of the Hottentot Fig, Carpobrotus edulis x acinaciformis.
Threat
The Hottentot Fig is a hardy plant that can survive in poor soils and endure drought conditions and exposure
to sea spray. These qualities have meant that they form healthy, impenetrable mats that exclude
native species. It is mainly an invasive of dune-type habitat, as can be seen on the Great Sand Slopes,
and is capable of suppressing the growth of both native seedlings (D’Antonio 1993) and mature native
shrubs (D’Antonio and Mahall 1991). The Hottentot Fig is capable of lowering the soil pH in loamy sand
(D’Antonio 1990a), and has been found to change the root system morphology of some native shrub
species in California coastal scrub (D’Antonio and Mahall 1991).
In Gibraltar, the Hottentot Fig soon covers extensive areas that dominate habitats, excluding the growth
of most native species. It is therefore a serious invasive that is classified as very problematic (vp). We are
lucky that the plant does not set seed. Nevertheless, it is an aggressive species that requires total eradication
from natural habitats. However, it may continue to be used as an ornamental garden plant, except
in locations where there is a likelihood that the species may invade natural wild habitats. The restoration
of the Great Sand Slopes has opened up a potential area for invasion by this species, although the angle
of the slope will make any vegetative spread upwards difficult.
Action
The Hottentot Fig needs to be urgently removed, in particular from the Foreshore, Great Sand Slopes
and small pockets within the Upper Rock Nature Reserve, after which removal must continue from all other
sites in Gibraltar.
There are several methods that can be used. The most effective (although labour intensive) is the manual
removal of mats. This has been carried out successfully by GONHS in a number of areas on Windmill
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Hill Flats with the collaboration of visiting military personnel. It was also removed from the mound at Europa
Point as part of the ‘Clean up the World Campaign’ in September 2005, where a large area was cleared.
With enough manpower, large areas can be cleared quickly, but because the plant can grow shoots and
roots from any node, all live segments must be removed to prevent contact with the soil and resprouting.
Removal using this method can be done at any time of the year but late summer is recommended because
the water content of plants will be lower and they will consequently weigh less.
The plant has few pest species associated with it, and these are ineffective as biocontrol methods. Two
species of scale insect, Pulvinariella mesembryanthemi and P. delottoi have been identified but their impact
on the plant is negligible (Washburn and Frankie 1985). The parasitic plant Dodder Cuscuta planiflora,
which is found in Gibraltar, has also been associated with this species, but its impact is again minimal.
Chemical control using herbicides has been successfully used. Guerreiro (1976) recommends
glyphosate at 5.4 kg/ha as the most rapid and complete control; with 3.6 kg/ha control still excellent
although less swift. Paraquat + simazine at 1.6 + 3 kg/ha is also satisfactory and benzoylprop-ethyl at 2
kg/ha will provide an adequate control. Adding an acidifier to hard water will increase its effectiveness, and
including a 1% surfactant to break apart the cuticle on the leaves increases mortality (Albert, Cal-IPC).
Herbicides should not be used on small patches of the plant that can be removed manually, as native plant
species could be affected. Late summer and autumn application of herbicides is best, as this impacts less
on dormant native species.
Further Reading:
• Suehs, C. M.; Médail, F.; Affre, L. (2001) Ecological and genetic features of the invasion by the alien
Carpobrotus plants in Mediterranean island habitats. In: Brundu G, Brock J, Camarda L, Child L
and Wade M, eds. Plant Invasions: Species Ecology and Ecosystem Management. Leiden:
Backhuys Publishers. 145-158.
• Brundu, G.; Brock, J.; Camarda, I.; Child, L.; Wade, M. (2001) Plant invasions: species ecology and
ecosystem management, pp.145-157.
• D'Antonio, C. M. (1993) Mechanisms controlling invasion of coastal plant communities by the alien
succulent Carpobrotus edulis. Ecology, 74: 83-95.
• D'Antonio, C. M.; Odion, D. C.; Tyler, C. M. (1993) Invasion of maritime chaparral by introduced succulent
Carpobrotus edulis. Oecologia, 95: 14-21.
• Guerreiro, A. R. (1976) Evaluation trials for herbicides to control Hottentot-fig (Carpobrotus edulis (L.)
N.E.Br.). [FT: Ensaios de comportamento de herbicidas contra os choroes (Carpobrotus edulis
(L.) N.E. Br.).] Proceedings II Simposio Nacional de Herbologia, Oeiras, 1977, No.Volume III,
pp.125-134, 18 ref.
• Weber, E.; D'Antonio, C. M. (1999) Phenotypic plasticity in hybridizing Carpobrotus spp. (Aizoaceae)
from coastal California and its role in plant invasion. Canadian Journal of Botany, 77: 1411-1418
• Vilà, M.; Weber, E.; D'Antonio, C. M. (1998) Flowering and mating system in hybridizing Carpobrotus
(Aizoaceae) in coastal California. Canadian Journal of Botany, 76: 1165-1169.
• Vilà, M.; D'Antonio, C. M. (1998) Fruit choice and seed dispersal of invasive vs. non-invasive
Carpobrotus (Aizoaceae) in coastal California. Ecology, 3: 1053-1060.

Class: Liliopsida Order: Asparagles Family: Iridaceae
AFRICAN CORNFLAG
Chasmanthe floribunda
Figure 17: African Cornflag Chasmanthe floribunda. (L. Linares).
Alien, Invasive & Pest Species
General Description
Commonly known as the African Cornflag, Chasmanthe floribunda is a geophytic perennial plant growing
to a height of 1m. The leaves are flat, broad and sword shaped, and the deep orange flowers, which
emerge in late winter and early spring, grow on either side of the central spike. The plants are mainly propagated
by the division of the corm, but they also set seed in Gibraltar. It is a drought resistant plant, preferring
well-drained soils and open, sunny locations.
Global Distribution
Native to South Africa where another two species of this genus can be found, the plant has been introduced
as an ornamental garden plant in many parts of the world including California, south-western
Australia and countries along the Mediterranean, where it has become naturalised and is considered a serious
invasive weed.
Local Distribution
Found mainly within the Upper Rock Nature Reserve, with a large stand of this species on the St.
Michael’s Cave firebreak. Also established in isolated patches around residential areas from where they
have spread, especially Ince’s and Bruce’s farms, Tovey Cottage, Jews’ Gate and the Cable Car top station.
Outside the Nature Reserve there are isolated pockets of the species on Windmill Hill.
Threat
Chasmanthe is classified as a very problematic invasive species that is rapidly spreading along open
areas within the Upper Rock Nature Reserve. It is outcompeting the indigenous flora for space and sunlight,
a flora that is already threatened by the encroachment of the dense maquis on firebreaks and open
areas. On the St. Michael’s firebreak, the plant has quickly spread to cover extensive areas of the slope,
replacing native species that formerly grew there, notably Iris filifolia. The problem has been aggravated
by the angle of the slope, which has aided seed dispersal. Isolated populations on the Upper Rock also
seem to be spreading, with new plants appearing around established stands every year.
Action
Control of this invasive is fairly straightforward since the species is found in open areas and concentrations
that enable their manual removal or the application of herbicides quite easy. Manual removal of the
corms in the late summer and autumn in areas where the soil is less stony is recommended. The application
of herbicides just after growth has started in the autumn is also a useful way to eliminate the plant.
This species should also be removed from gardens within the Reserve and included in the list of plants
that should not be introduced as a garden plant in the Upper Rock Nature Reserve (Perez & Bensusan
2005).
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Class: Magnoliopsida Order: Caryophyllales Family: Aizoaceae
PURPLE DEWPLANT
Disphyma crassifolium
Figure 18: Purple Dewplant Disphyma crassifolium. (L. Linares).
General Description
The Purple Dewplant or Round-leaved Pigface is a salt resistant prostrate, ground-hugging, mat-forming
succulent shrub with clavate leaves and a generally rounded keel. It flowers in the spring with innumerable
reddish-violet flowers forming an attractive mat on the ground, and reproduces vegetatively.
Global Distribution
Native of South Africa, the plant has been introduced to Western Australia, California, and
Mediterranean countries where it has become widely naturalised.
Local Distribution
Found mainly along the cliffs around Europa where the plant forms dense mats, and down on the
Europa Foreshore.
Threat
Disphyma has been classified as being a potential problematic plant. The plant forms a dense mat that
excludes native vegetation in a similar way as the Hottentot Fig Carpobrotus edulis x acinaciformis. At the
moment the plant does cover an extensive area of cliff opposite the Governor’s Cottage, and excludes and
smothers the Gibraltar Sea Lavender. Another stand is found in the yard of the Lighthouse and both are
contained from spreading by the sea cliff and roadside walls.
Action
If at any time the species was capable of setting seed or established itself in other areas where it could
spread extensively, then the species would be re-classified as problematic and would require a specific control
programme.
For the time being the species will only require regular monitoring.

Class: Magnoliopsida Order: Lamiales Family: Verbenaceae
BUSH LANTANA OR SHRUB VERBENA
Lantana camara
Figure 19: Bush Lantana Lantana camara (L. Linares).
Alien, Invasive & Pest Species
General Description
The Shrub Verbena or Bush Lantana is a rugged, evergreen shrub capable of growing up to 2m high
and spreading up to 3m wide. Some varieties are able to clamber up, supported on other shrubs, and reach
greater heights. It has a strong root system and sprouts vigorously after pruning. The stems are woody
with spines and rough hairs, and the rough green leaves emit an unpleasant smell when crushed. The
species flowers throughout the year in clusters of mainly yellow, orange and red flowers, with white or purple
in some varieties. It sets a cluster of green fruit that turns purple when ripe and is poisonous to pets,
although ingested by birds. Lantana is a drought resistant plant that also does well in humid conditions but
does not tolerate frost.
Global Distribution
Originally a native of the West Indies. Introduced to the Pacific Island nations, it also occurs in Australia,
New Zealand, China, Thailand, Cambodia, Viet Nam, Malaysia, Indonesia, the Philippines, the
Mediterranean, and some parts of sub-Saharan Africa.
Local Distribution
Grown as a hedge plant for its evergreen leaves and colourful flowers, Lantana is a common ornamental
plant in Gibraltar. Spreads by self-seeding in the Botanic Gardens, especially in areas where the ground
is watered at least occasionally. Recently found naturalised in the wild within the Upper Rock Nature
Reserve where several plants were discovered in 2004.
Threat
This species has been nominated as being among the 100 ‘World’s Worst’ invaders by the IUCN
Invasive Species Specialist Group and is classified locally as a potentially problematic invasive species.
Lantana is an understorey competitor where it will out-compete the native plants and cover extensive areas,
forming dense, impenetrable vegetation.
Seed ingestion by birds seems to have been the method of dispersal of the newly discovered plants.
These plants, one of which is a relatively mature shrub, are devoid of the ample leaf cover found in garden
specimens, and do not seem to fare well in the stony soils of the Upper Rock. It therefore seems probable
that the plant is not suited to the environmental conditions found within the Upper Rock Nature Reserve.
Nevertheless, the potential threat remains and the best solution in order to avoid any future problems would
be to remove any plants found growing in the wild.
Action
Identify the location where plants are growing in the wild and manually remove these by cutting down
and uprooting the plants. The cultivation of this plant in Gardens within the Nature Reserve should be prohibited.
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Class: Magnoliopsida Order: Solanales Family: Solanaceae
SHRUB TOBACCO
Nicotiana glauca
Figure 20: Shrub Tobacco Nicotiana glauca. (L. Linares).
General Description
The Tree or Shrub Tobacco is a rapidly growing, small tree with straggling branches reaching some 4-
8m in height. Its leaves are ovate, pale green and rubbery in texture. It flowers in warm conditions from
spring to late autumn, with yellow cylindrical flowers that are able to produce from 10,000 to 1,000,000
small seeds on a single shrub. Young plants grow very quickly in poor and disturbed sandy and welldrained
soils, and are able to tolerate drought conditions and some salinity. It is closely related to the
Tobacco plant but does not contain nicotine.
Global Distribution
Native to Bolivia and Argentina, but introduced as an ornamental garden plant in Mediterranean climes
where it has become naturalised. Invasive in Mexico, South Africa, Israel, Australasia North America and
Europe.
Local Distribution
This species seems to colonise and grow rapidly in disturbed areas (it was the first shrub to colonise
the reclamation area on the eastern side), but is then overtaken by the growth of indigenous species and
struggles to maintain a foothold. It is found mainly along the eastern side of the Rock in sandy habitats
along the Talus slopes and the Great Sand Slopes, which it invaded as soon as the water catchment sheets
were removed. This species was one of the dominant plants here but has since died back and allowed
other native species to grow. Also found in small numbers along the rock catchment area from Camp Bay
to Little Bay, the Europa Point area and the Europa Foreshore, with smaller numbers of plants on the
Isthmus. They also grow in the urban habitat from crevices in old walls and buildings.
Threat
The species is classified as problematic, given the invasive capability of the plant to colonise new and
disturbed areas. Nevertheless the Shrub Tobacco has not proved to be a lasting threat since many of the
plants fare poorly on attaining maximum growth, and do not seem to affect the native flora adversely for
any length of time.

Alien, Invasive & Pest Species
Action
Monitoring of the species and assessing its invasive tendencies and survivorship, and surveying the
species’ distribution on the eastern side of the Rock to ensure that the plant is dying back seem to be the
only requirements, since the species does not seem, for the moment, to be affecting the indigenous flora
negatively.
Further Reading:
• Conant, P. et al. (1997) Appendix. Selected plant species interfering with resource management goals
in North American natural areas. In: J. O. Luken & J. W. Thieret, eds., Assessment and management
of plant invasions. (Pl Invasion).
• Goodspeed, T. H. (1954) The genus Nicotiana. Chron. Bot., 16: 335.
• Henderson, L. (2001) Alien weeds and invasive plants: a complete guide to declared weeds and
invaders in South Africa. Plant Protection Research Institute, Handbook 12. (Weeds SAfr 2001).
• Weber, E. (2003) Invasive plant species of the world: a reference guide to environmental weeds.
(Invasive Pl Spec).
Class: Magnoliopsida Order: Caryophyllales Family: Cactaceae
PRICKLY PEAR
Opuntia ficus-indica
Figure 21: The Prickly Pear Opuntia ficus-indica in flower. (L. Linares).
General Description
The Prickly pear, an evergreen perennial, is a massive, trunk-forming, segmented cactus, bearing large
pad like leaves called cladodes, with few spines. The species flowers on the perimeter of the pad, and yellow
or orange cup-like flowers bloom in late spring and early summer. The round, 10cm-long, green fruit,
surrounded by masses of very short spines, ripen in the early autumn and turn orange to purple in colour.
The fruit is edible.
Global Distribution
The original habitat of this species is uncertain although they originate in the Americas and are believed to
be native to Mexico. Introduced to other countries worldwide, they have become naturalised in Argentina,
China, Ethiopia, Haiti, Sicily and Spain and have become an invasive species in Australia and South Africa.
Local Distribution
Cultivated in the surrounding region for their fruit and also previously used as a boundary hedge plant,
the prickly pear has a wide local distribution.
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Figure 22: Distribution of the Prickly Pear
Opuntia ficus-indica in the south of Gibraltar.
The main stronghold is in the area of Hole in the Wall, where in the last
twenty years they have spread to cover large areas of the rocky slopes,
and are extending along the cliff up towards Mediterranean steps and the
Upper Rock Nature Reserve. Also abundant around the Ince’s Farm and
Devil’s Gap area from where it is believed they spread. The species has
now extended to cover large areas of the surrounding, west-facing cliffs
and is beginning to spread further into the Nature Reserve. Smaller, isolated
stands can be found around the Bruce’s Farm and PSA Nursery area,
Tovey Cottage and the east side cliffs above the Sand Slopes just below
Middle Hill. Another important stand can be seen down on Europa
Foreshore in the company of other invasives, and isolated plants are located
in the North Gorge, around Camp Bay and Sandy Bay.
Figure 23: Distribution of the
Prickly Pear Opuntia ficus-indica
in the centre of Gibraltar.
Threat
The threat to biodiversity caused by the Prickly Pear is
immense. The species already covers extensive sensitive areas
of habitat, particularly the foreshore and around Hole in the Wall,
where several important species of plant are being threatened by
the continual expansion of this species. The Upper Rock Nature
Reserve is also under threat, in particular Mediterranean Steps,
a unique cliff habitat area of great environmental value. This site is being threatened by the spread of the
species along the cliffs from the Hole in the Wall. The Devil’s Gap/Bruce’s farm area, where the species is
rapidly spreading, is also threatened.
Figure 24: The Prickly Pear Opuntia ficus-indica at Hole in the Wall. Only
the Dwarf Fan Palm, Chamaerops humilis can penetrate this dense cover.

Alien, Invasive & Pest Species
The prickly pear has been present at these localities for many years, but in the last decade some
unknown environmental factors seem to have favoured the spread of this species, and it is now regarded
as a serious problem and classified as very problematic.
The eradication of the plant from the wild in Gibraltar is seen as an essential step in conserving some
of the Rock’s more important habitats.
Action
The establishment of a programme for the eradication of this species in the wild is a priority. There are
several control methods that have been used widely, especially in Australia and South Africa, where the
species has reached invasive proportions. In these two countries the extent of the invasions has necessitated
the use of biocontrol agents. Several have been identified, tested and used and have proved
amongst the most effective entomological control methods ever used in controlling an invasive species.
Amongst these is the cactus moth, Cactoblastis cactorum (a native of South America) that was introduced
during the 1930s, when the South African Parliament declared prickly pear a national disaster. This species
effectively controls the spread of the wild prickly pear, while allowing the cultivation of the food crop, the
cactus pear. Cactus pear growers regard the moth as a pest, but this species can be controlled by the use
of pesticides. This species was also effectively used in Australia where they were used successfully against
O. ficus-indica and O. stricta (Klein, 2002).
Cochineal insects, sap-sucking insects that feed on the cactus, are also used. The species Dactylopius
opuntiae of the ‘ficus biotype’ is the biocontrol agent of the Prickly Pear (Klein, 2002).
Another two biocontrol agents were tested in South Africa but did not contribute significantly towards
the control of the species, although they did damage the plants. These were the beetles Metamasius spinolae,
which is the most destructive cactus insect in its native range and Archlagocherius funestus, which
attacks only Prickly Pear but caused little damage to the plants.
The Prickly Pear can also be controlled through the application of herbicides. A similar invasive species,
Opuntia stricta, was affecting the Dom António Xavier Pereira Coutinho Nature Reserve in Portugal.
Different approaches were assessed simultaneously and the use of glyphosate directly to the plants
through injection into the cladodes and stem in the summer proved the most effective (Monteiro et al. 2005).
The herbicide Roundup is effective on the Prickly Pear and the makers recommend the use of Roundup
on Opuntia ficus-indica as an application injected into pre-made holes in the stems of trees with 20-250
cladodes, applying 2ml of an 18% solution of the product. Roundup is registered for use against Bugweed,
Bramble, Lantana, Prickly Pear, and Water Hyacinth. It kills all green plants, grasses included. It is usually
applied as a leaf spray at a concentration of 1-2% in clean water. It is not poisonous to animal life and deactivates
upon contact with soil. Roundup can also be used as a 2-4% solution to spay onto freshly cut stumps.
Physical removal of the plant is not effective and for those plants established on cliffs, impossible. The
species germinates easily and sets root from leaf cladodes that have been torn or discarded. Therefore,
the complete removal of the plant is essential to avoid accidental propagation.
In Gibraltar the possibility of the use of the biocontrol agent, the moth Cactoblastis cactorum, should be
investigated. However, the devastating effect that this may have on prickly pear crops in the region must
be taken into consideration, and other methods must be favoured if possible. There are several species of
Opuntia of conservation value growing in the Botanic Gardens and these would be adversely affected by
the moth, although these could be treated against the moth with pesticides.
A serious attempt should be made to treat prickly pear populations with glyphosate herbicides, using
GONHS Cliffs and Caves Section to access those on cliffs.
Further Reading:
• Hernandez, L.R.; Emmel, T.C. (1993) Cactoblastis cactorum in Cuba (Lepidoptera: Pyralidae:
Phycitinae). Tropical Lepidoptera, 4: 45-46.
• Johnson, D.M.; Stiling, P.D. (1996) Host specificity of Cactoblastis cactorum (Lepidoptera:
Pyralidae), an exotic Opuntia-feeding moth, in Florida. Environmental Entomology, 25: 743-748.
• Mahr, D.L. (2001) Cactoblastis cactorum (Lepidoptera: Pyralidae) in North America: a workshop of
assessment and planning. Florida Entomologist, 84: 465-473.
• Mayra Perez-Sandi, C. (2001) Addressing the threat of Cactoblastis cactorum (Lepidoptera:
¨Pyralidae), to Opuntia in Mexico. Florida Entomologist, 84: 499-502.
• Monteiro A., Cheia VM., Vasconcelos T., & Moreira I. (2005) Management of the invasive species
Opuntia stricta in a Botanical Reserve in Portugal. Weed Research 45: 193–201.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Class: Magnoliopsida Order: Oxalidales Family: Oxalidaceae
BERMUDA BUTTERCUP
Oxalis pes-caprae
Figure 25: Bermuda Buttercup Oxalis pes-caprae. (L. Linares).
General Description
The Bermuda Buttercup is a small, perennial plant that germinates in the late autumn and winter after
the first rains. Known locally as the ‘Vinagretta’ or “Vinagrera”, referring to the vinegary, sour-tasting oxalic
acid present throughout the plant, the shoots of Oxalis arise from a pale brown bulb that is capable of
producing over 20 whitish bulbils each year. Leaves arise from a succulent basal stem tip in a cloverleaf
form or cloven shape. Pes-caprae, meaning goat foot, refers to the shape of the leaf. The species flowers
in late winter and early spring, much earlier than most native species, and bears several bright yellow
flowers, sometimes double. Locally it is unable to set seed, but spreads through the production of vast
quantities of bulbils.
Global Distribution
Native to the Cape region of South Africa, the Bermuda Buttercup is associated with Mediterranean climates
and has been introduced to Italy, Greece, the Iberian Peninsula and North Africa and Australia where
it is widely invasive (Pierce, 1997). It has also been recorded in North America from California, Florida and
Arizona where it is recently becoming a serious problem (Elmore & Cudney, 2002).
Local Distribution
Kelaart (1846) claimed that it arrived in Gibraltar around 1836 as he had been informed by a Captain
Mitchell that it was not found in Gibraltar before then. Wolley Dod (1914) stated that it has “increased enormously
in recent years”. It has now become established as a dominant species and can be found wherever
the soil has been disturbed, especially in the south where the species can be seen commonly everywhere,
including the cliffs that appear with a yellow mantle in late winter during the flowering period.
Restricted mainly to roadsides, firebreaks and open areas within the Upper Rock Nature Reserve, the
species appears to be on the increase. Also sparsely found on the Great Sand Slopes but already well
established on the Talus slopes and the Isthmus.
Threat
Oxalis is a weed that forms dense mats on the ground,
outcompeting the native plant species. Brooks (2001) has
found that it inhibits the germination of native species, causes
soil enrichment and alters the ecosystem nutrient cycle.
The species has been classified as problematic (p).
Figure 26: The Bermuda Buttercup covering
part of the Sand slopes. (L. Linares)

Alien, Invasive & Pest Species
We cannot be certain what damage this species has already caused, but it is now established as a dominant
species that is virtually impossible to eradicate. Found even in inaccessible areas on cliffs, this
species, although potentially competing with native species, germinates and flowers so early in the season
that it wilts and dies back when much of the native flora is beginning to sprout. However, competition with
native bulbous species is a possibility of serious concern, and this would include the orchids.
The continual scraping of the vegetation and soil along the roadsides on the Upper Rock is aiding the
spread of bulbils north to areas where the species was less common.
Action
Very little can be done to address the problem of this invasive, which is now well established, although
there are several recommendations that can stop the spread of the species to other areas in Gibraltar.
Disturbed soils and habitats that show germination of Oxalis should be treated with herbicides and Kelly
(2002) reports that glyphosate in a 2% solution just before flowering, achieves a 95% kill rate. Nevertheless
the bulbils germinate rapidly, so the areas need to be treated again. Mowing can also deplete the carbohydrate
reserves in the bulbs but this needs to be done repeatedly. Roadside scraping and removal of the
vegetation on the Upper Rock Nature Reserve is futile and should only take place in the early summer to
remove the dry vegetable matter as a fire prevention exercise. This recommendation was included in the
Upper Rock Nature Reserve, A Management and Action Plan (Perez & Bensusan, 2005), but the practice
continues. The situation has been further aggravated by the use of strimmers along the same roadsides.
No biocontrol agents are available although Kluge & Claassens (1990) reported a potential agent in the
form of the moth larvae of Klugeana philoxalis that feeds on the shoots of Oxalis.
Given the difficulty of eradicating this species, control methods should only be applied where there is a
potential risk of invasion to otherwise Oxalis-free habitats or danger to the welfare of scarce and rare native
species of flora.
Class: Magnoliopsida Order: Fabales Family: Fabaceae
CAPE WATTLE
Paraserianthes lophantha
Figure 27: The Cape Wattle Paraserianthes lophantha.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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General Description
A straggly shrub or small tree growing to a height of 6 metres, although normally shorter. Twigs are
slightly ribbed and leaves are compound, composed of numerous small leaflets similar to many Acacias.
The flowers are also similar to those of Acacias, cream yellow in colour, and sprout in a bottlebrush-like
cluster. The seedpods are large, broad and flat, each containing between 6-12 shiny black seeds. Like the
true Wattles, the Cape Wattle produces huge seed crops, which survive for long periods in the soil.
Global Distribution
The Cape Wattle is a native of Western Australia that has been introduced as a garden plant and is now
extensively naturalised in Eastern Australia. It has been introduced to many countries in the Mediterranean
region as an ornamental garden plant, and has spread into the wild.
Local Distribution
Located on the Lower Slopes below Devil’s Gap, where there are several trees along the footpath to
town, from where it seems to be spreading along Green Lane. Elsewhere there are a few individual trees
along the car park north of Catalan Bay, which were established through the transfer of some of the material
from the Camp Bay rockfall that was deposited there. At Camp Bay there was one old tree that was
buried by the rockfall. The rockfall material was then utilised to form a slope at that location and along the
base of cliff running to the desalination plant outfall, from where many seeds germinated to form a dense
thicket of young plants of this species. Two other specimens can be found on the Rock: one that has
recently become established in the middle of the Great Sand Slopes and another located close to St.
Bernard’s Church in the Europa Point area.
Threat
The Cape Wattle is a fast growing plant that is tolerant of poor soils. It is classified as very problematic
(vp) and has obviously done well in the disturbed rocky waste material that was deposited at Camp Bay.
It is adapted to recolonising from seed after fire and germinates profusely to dominate the area if there is
no control. This particular slope at Camp Bay was affected by fire on 3 rd June 2002 (CFB 2002), after which
there was a spontaneous germination of plants that have now spread all the way up the slope and are on
the verge of invading the Old Naval Hospital residential area, from where it is likely to spread further.
The Lower Slopes stand is already spreading at a worrying rate and several specimens can be found
within the Nature Reserve just below Ince’s Farm.
The one plant on the Great Sand Slopes grows in the area that was burnt in 2005. Given the rapid germination
after fire, there is the possibility that the species will spread all over this area.
Action
The eradication of this species is an urgent priority. The specimen on the Great Sand Slopes must be
removed immediately and the site regularly monitored to ensure that this species and other invasives do
not germinate at this site.
Similarly the wattle thickets at Camp Bay and the Lower Slopes need urgent removal to stem the spread
of the species.
Several methods are used in Australia for the control and removal of this species. Amongst these is
hand-pulling, where seedlings and small shrubs can be removed by hand when the soil is moist. This may
not be possible in Gibraltar due to the stony nature of the soil. Ring barking of larger plants may be applied
as close to the ground as possible. This involves stripping a ring of bark that will stop the growth and in
many cases kill the tree altogether. Herbicides can also be applied to the foliage using a glyphosate product,
of which there are many different brands available. It can also be applied into a cut in the bark near
the ground or painted on. The biocontrol agent, the weevil Melanterius servulus, mentioned under Acacia
cyclops, is also effective against this species.
Further Reading:
• Cronk, Quentin C. B., and J. L. Fuller. (1995) Plant invaders. Chapman and Hall. 241 pp.
• Henderson, L. (1995) Plant invaders of Southern Africa. Plant Protection Research Institute
Handbook No. 5, Agriculture Research Council, ARC/LNR, Pretoria, South Africa.177 pp.
• Hickman, J. C. (1993) The Jepson manual: higher plants of California. U. Cal. Press, Berkeley. p. 583.

Class: Liliopsida Order: Poaceae Family: Paniceae
KIKUYU GRASS
Pennisetum clandestinum
Figure 28: The Kikuyu Grass Pennisetum clandestinum. (L. Linares).
Alien, Invasive & Pest Species
General Description
Pennisetum clandestinum is a creeping, mat forming grass composed of creeping rhizomes and stolons
with overlapping leaf sheaths. It flowers from vegetative side shoots with only the stamens visible above
the leaves (Holm et.al., 1977).
Global Distribution
The Kikuyu grass originates from tropical east Africa and gets its name from its native area where the
Kikuyu tribe originates. Used as a lawn grass, it has been introduced worldwide and can be found in
Australia, New Zealand and many South Pacific Islands, North America, Colombia, Peru, Costa Rica and
Ecuador in Central and South America, the Indian sub-continent and China and Taiwan.
Local Distribution
This species has spread from the site of the old Royal Navy satellite tracking station on Windmill Hill
into the surrounding habitat. From here it has found its way onto the rifle shooting range and along the
roadside to the east of Buffadero. Also established on the disused construction site beside Maida Vale
where the rhizomes hang several metres down the wall onto the main roadway leading to the Upper Rock,
and opposite the Bishop’s House, where it is beginning to creep up and into the surrounding vegetation,
although here it is restricted by the dense high maquis, for the species is intolerant of dense shade.
Threat
Kikuyu grass is a very aggressive invader of pastures, crops, and natural habitats and is regarded as a
crop weed of 14 crops in 36 countries (Holm et.al., 1977). Spreading via an extensive network of rhizomes
and stolons, it smothers all the surrounding vegetation including shrubs and young trees. On Windmill Hill,
it covers an extensive area that was once rich with native species of plants. Now, the Kikuyu grass covers
all the growth and competes for the natural resources and sunlight, impeding the germination of native
species. It is also capable of producing allelopathic chemicals that kill other plant species in its vicinity
(Sanchez & Davis, 1969).
This species is classified as very problematic (vp) and should be eradicated in its entirety from Gibraltar.
The Kikuyu Grass probably spread to Maida Vale from adjacent gardens, and to other areas of Windmill
Hill through the transportation of small pieces of rhizomes and stolons on military vehicles and soldiers’
boots and clothing.
Action
Kikuyu grass is very difficult to control manually, but the use of herbicides yields good results.
Physically, all the rhizomes must be dug out to prevent re-sprouting and the local nature of the stony soil
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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renders this practically impossible. Timmins & Mackenzie (1995) recommend the use of several herbicides
as a useful control method, amongst which the following products and dilutions are the best; Roundup
(without Pulse) 1%, Dowpon 740-SP (16-20 g/l sater), Gallant (0.5%). To allow desirable species to reestablish
themselves, the application of methylarsonic acid (MSMA) and triclopyr may reduce the competitive
ability of P. clandestinum (Cudney et. al., 1993 in Haubensak & Smyth, 1999).
GONHS has already begun to address the Kikuyu grass problem on Windmill Hill. In the spring and
summer of 2005 some of the areas were treated with Roundup, and this was continued again in the
autumn. This was done through the efforts of the site supervisor WO II Peter Jackson, who undertook to
apply the herbicide himself. The site must be monitored to assess the impact of the herbicide on the invasive
plant, and more importantly on native species of flora. Application during the dry period seems to be
more effective as the herbicide remains in contact for longer with the plant, the plants natural reserves are
at its lowest levels, and most native species are dormant.
Other areas, especially those found around Maida Vale must be tackled before the species spreads any
further, and the use of this species as a turf grass in Gibraltar must be controlled or banned altogether, as
the risk of invasion is too great.
There are no biocontrol methods available although some natural agents do affect the well-being of the
kikuyu grass in part. The rust fungus Phakopsora apoda appears to reduce the photosynthetic capacity of
the leaves in South Africa, but does not kill the plant (Adendorff & Rijkenberg, 1995) and a fungal disease
caused by Pyricularia grisea kills seedlings (FAO, 2003).
Further Reading:
• Conant, P. et al. (1997) Appendix. Selected plant species interfering with resource management goals
in North American natural areas. In J. O. Luken & J. W. Thieret, eds., Assessment and management
of plant invasions. (Pl Invasion)
• Henderson, L. (2001) Alien weeds and invasive plants: a complete guide to declared weeds and
invaders in South Africa. Plant Protection Research Institute, Handbook 12. (Weeds SAfr 2001).
• Weber, E. (2003). Invasive plant species of the world: a reference guide to environmental weeds.
(Invasive Pl Spec).
• Wong, F. P., (2004) First report of Pyricularia grisea Causing Gray Leaf Spot on Kikuyugrass
(Pennisetum clandestinum) in the United States. University of California, Department of Plant
Pathology. San Diego.
Class: Magnoliopsida Order: Asterales Family: Asteraceae
CAPE IVY
Senecio angulatus
Figure 29: The Cape Ivy Senecio angulatus.

Alien, Invasive & Pest Species
General Description
Known as the Cape Ivy, this is a creeping and climbing perennial shrub, entwining around supporting
vegetation that can reach a height of over 6m. It has thick, fleshy, glossy, bluntly lobed leaves with one to
three teeth on either side. Produces yellow daisy flowers in late autumn and winter, and later feathered
seeds that spread easily.
Global Distribution
A native of South Africa, this species has been introduced as an ornamental
garden plant to countries in the Mediterranean, Australia and
California, from where it has become naturalised in the wild as a pest, invasive
species.
Local Distribution
Found mainly behind the Rock Hotel above Europa Road from where it
must have presumably spread. Also established on the Lower Slopes along
the Footpath to town and within the Upper Rock Nature Reserve where it has
escaped from gardens, in particular Bruce’s Farm, Ince’s Farm, the Devil’s
Gap residential area and the PSA Nursery. Elsewhere the species can be
seen on cliffs around Parson’s Lodge, as a ground creeping plant at the
entrance to the Governor’s Cottage on Europa Advance Road, and in the
vicinity of the gardens of the derelict ‘Rockfall’ house at the entrance to
Catalan Bay. Isolated plants can be found in urban areas within the town.
Figure 30: Main affected areas of the
invasive Cape Ivy, Senecio angulatus.
Threat
A very invasive and aggressive plant in the understorey of open woodland that climbs and smothers
shrubs and trees. Particularly aggressive along the lower Rock behind the Rock Hotel gardens where it covers
mature olive trees and shrubs with its creepers, blotting out the sunlight and creating an impenetrable
mass that covers a huge area. It has also spread from the PSA Nursery, in the Upper Rock Nature
Reserve, into the adjacent woodland where it smothers all adjacent vegetation.
This species is doing much damage to the biodiversity of the high maquis habitat and is restricting and
in places impeding the growth of understorey species of native plants. The species has been classified as
very problematic and requires urgent eradication, especially those found in the main affected areas that can
be seen in the distribution map. Significant parts of the Upper Rock Nature Reserve run the risk of being
smothered by this species if urgent action is not carried out.
Action
Due to the extent of this invasive plant, a great deal of manpower is required to successfully remove the
species. Several different methods can be used, including hacking away at the creepers and allowing them
to rot away on the trees. The cut stems require attention. Herbicides will do the job, but this requires regular
application. The following recommendations have been reproduced from the ‘Greater Wellington
Regional Council’ web page. (http://www.gw.govt.nz).
Treatment methods
• Hand pull or dig out small plants. Dispose of the roots carefully to avoid dispersal.
• Cut stems below waist height, and then spray below this point: glyphosate 10ml/L water; or 2g Escort
+ penetrant/10L water.
• Stump swab: Escort 5g/L water; or glyphosate 100ml/L water.
• Follow-up work is required.
Work has already begun on the plants found within the PSA Nursery through manual control by a group
of volunteers from GONHS who have continually hacked away and uncovered large areas that were once
smothered by this species. They have also revealed the extent of the damage when several examples of
stunted Almond saplings were uncovered from this dense impenetrable mass.
The invasive species problem within the Nature Reserve should be tackled by the works team recommended
in the chapter on introduced flora in ‘Upper Rock Nature Reserve. A Management and Action Plan’
(Perez & Bensusan, 2005). This works team could also be employed to tackle the invasive flora elsewhere
in Gibraltar.
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Class: Magnoliophyta Order: Brassicales Family: Tropaeolaceae
NASTURTIUM
Tropaeolum majus
Figure 31: Nasturtium Tropaeolum majus. (L. Linares).
General Description
The Nasturtium is a glabrous, somewhat succulent annual that has vine-like climbing stems that spread
along the ground and smother trees and shrubs. The leaves are rounded and bright green and the plant
flowers in the spring with orange to reddish orange petals that are sometimes streaked with red. Plants are
propagated through seeds, vine-like runners and cuttings.
Global Distribution
Native to the Andes Mountains, mainly around Peru, in South America, the plant has been introduced
worldwide as an ornamental garden plant where in some countries it has become naturalised in the wild.
Local Distribution
Found mainly in three areas in the wild in Gibraltar: opposite the entrance to the Bishop’s House on
Engineer Road, where the plant grows profusely in the open areas (competing with the other invasive, the
grass Pennisetum clandestinum, to the detriment of indigenous flora), in an open area at the entrance to
Devil’s Gap where the plant is contained between the base of the cliff and the road and covers an extensive
area, and south of the Calpe residential area along Willis’s Road, on the old water catchment around
the lower entrance to the Waterworks.
Threat
This species is classified as problematic (p) and is an aggressive invasive species that tends to form a
blanket of leaves, smothering the surrounding vegetation. It prefers open ground in sunny locations and
does not do well in shady conditions. It is therefore contained in the small area on Engineer Road as the
dense high maquis is preventing its expansion into the Nature Reserve. Nevertheless there is the danger
that seeds and small cuttings may accidentally be propagated to other areas of Gibraltar.
The stand at Devil’s Gap is more worrying, since the open terrain around the Lower Slopes is an ideal
habitat for this species to spread. At the moment it is contained within the base of the cliff and the road,
but already there are some plants that have jumped this barrier and are beginning to spread along the
slopes.
The stand at the Waterworks is also contained within the water catchment bordered by Willis’s Road,
but there is a danger that the species will spread into the Nature Reserve.
Action
This plant needs to be tackled urgently, especially the stand at Devil’s Gap (in order to avoid propagation
further into the Lower Slopes) and that at the Waterworks. The application of herbicides sprayed directly
onto the plant is recommended as a useful control method, amongst which the following products and
dilutions are the best: Roundup (without Pulse) 1%, Dowpon 740-SP (16-20 g/l sater), Gallant (0.5%). The
New Zealand ‘Environment Bay of Plenty’ Regional Council (www.ebop.govt.nz/weeds/weed308.asp), recommends
the use of spraying with Glyphosate + Penetrant as more appropriate than hand pulling for large
infestations (Rate - Handgun 1 litre Glyphosate + 200 ml Penetrant/100 litres water. Knapsack 100 ml
Glyphosate + 20 ml Penetrant/10 litres water).

Class: Liliopsida Order: Asparagales Family: Agavaceae
SPINELESS YUCCA
Yucca elephantipes
Figure 32: The Spineless Yucca, Yucca elephantipes.
Alien, Invasive & Pest Species
General Description
The Spineless, Elephant foot or Giant Yucca is a formidable shrub capable of growing up to 9m in
height. Mature specimens have a rough and thick trunk that develops a swollen base, hence its scientific
name. The shiny green leaves form a spiral rosette that is pliable and lacks the sharp spines found in most
Yucca species. The plant often branches a metre off the ground and flowers in winter and early spring on
tall stalks with white bell-shaped clusters of flowers.
Global Distribution
Native of Southern Mexico and Central America, it has been introduced
to many countries as a popular ornamental garden plant.
Local Distribution
Planted in urban areas around Gibraltar as an ornamental plant, but
found naturalised on the edge of the Great Sand Slopes along the
northern channel of the Water Catchments where they must have presumably
been initially planted and from where they are now spreading.
Figure 33: Distribution of Spineless Yucca,
Yucca elephantipes.
Threat
The plant is classified as potentially problematic (pp), since there is
a serious probability that the species could spread along the Great
Sand Slopes. There are already indications that the plant is spreading
from this location, although it is confined for the moment to this area. A
fire on the Great Sand Slopes in the late summer of 2005 killed several specimens of this plant.
Action
Not a serious problem yet. Nevertheless it is recommended that the plants be removed and included
in the eradication programme of invasive species on the Great Sand Slopes.
Uprooting the trunk bases from the sandy soil would be the best method as the plant is capable of rooting
if any part of the plant is left behind. The area should be monitored on an annual basis and included in
the alien invasive monitoring programme to ensure that the species does not become established again.
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Pest Species
A pest species is an injurious plant or animal, especially one harmful to humans. In this exercise we
classify pest species as those species that are detrimental to the indigenous biodiversity, and could also
have an impact on environment and human health. Pest species can either be native or naturalised.
These may have reached pest proportions due to environmental factors or a lack of natural control.
Species considered as pests that adversely affect Gibraltar’s biodiversity include:
• Bear’s Breech Acanthus mollis
• Black Rat Rattus alexandrinus
• Barbary Macaque Macaca sylvanus
• Feral Cat Felis catus
• Goat Capra hircus
• Feral Pigeon Columba livia (domest.)
• Yellow-legged Gull Larus michahellis
A pest species action plan is included for each except the Barbary Macaque, which is included under
the species action plans.
Class: Magnoliophyta Order: Laminales Family: Acanthaceae
BEAR’S BREECH
Acanthus mollis
Figure 34: Bear’s Breech Acanthus mollis. (L. Linares).
General Description
The Bear’s Breech is a herbaceous perennial that grows in upright clumps reaching a height of over a
metre. The leaves are very large, dark green, glossy, lobed and toothed, and shade out the surrounding
area completely. It grows impressive flower spikes with white and purple flowers that appear in mid April
and last until the end of May. Plants spread by thick, creeping rootstocks to form extensive colonies, and
by explosive seedpods. A hardy plant, tolerant of poor soils, that does well in full sun and partial shade.
Global Distribution
A native of Southern Europe, and North Africa. A favourite garden plant that has been introduced to
many countries including North America, Mexico, Cornwall in Britain, and in parts of Australia and Tasmania
where it is considered an invasive species.

Alien, Invasive & Pest Species
Local Distribution
Widespread around Gibraltar, and especially within the Upper Rock Nature Reserve where it has
increased in the last 25 years (Linares et al.1996; Linares 1997), and to a lesser extent, on the Lower
Slopes. It does well on firebreaks and is a dominant plant of the understorey in some maquis habitats.
Threat
Considered a fine foliage plant for garden shrub borders, Latymer (2001) nevertheless states that the
species should be used with caution, as it can easily become a pest and is difficult to remove since the
explosive pods scatter seed over a wide area, and plants will re-grow from any scrap of root. In the wild in
Gibraltar the plant tends to have invasive characteristics and does not seem to have any pathogens or a
natural biological control. It grows in large stands that cover extensive areas, out-competing the local
indigenous flora for sunlight and natural resources. Sprouting in winter, the leaves form a dense cover that
remains throughout the spring until late April and May, when the softer stemmed leaves soon wilt and begin
to die. The stronger-stemmed flower spikes remain upright and the seedpods dry and explode, scattering
large quantities of seed widely.
Areas where Acanthus is found are devoid of low growing native flora. This is especially serious on the
open areas of pseudosteppe habitat and firebreaks that are potentially a refuge for many scarce species of
flora.
Action
The eradication of Acanthus is difficult given the wide distribution of the plant around Gibraltar.
Nevertheless every effort should be made, especially when clearing roadsides, pathways and firebreaks to
remove this plant consistently and carefully to avoid seed dispersal. Other native plants may be allowed to
grow and it is therefore essential that those tasked with the eradication must be competent in the identification
of this and other plants that are detrimental to the environment.
The careful application of herbicides is recommended where large stands of Acanthus need to be
eliminated, such as on Bruce’s Farm firebreak.
Class: Mammalia Order: Rodentia Family: Muridae
BLACK RAT
Rattus rattus alexandrinus
Figure 35: Black Rat Rattus rattus alexandrinus
General Description
The subspecies of Black Rat R. r. alexandrinus, also known as the Alexandrine Rat, is a slender rat with
hairless ears that has a tail equal to its body length and a brown fur coat with a creamy white belly. In tropical
climates breeding takes place all year round, and the rat can have five of six litters depending on food
availability. However, in temperate climates breeding usually takes place in spring and autumn with one litter
of between 5-8 young. An omnivorous species that will feed on almost anything, the rats on the Upper
Rock are arboreal and feed mainly on fruit and seeds. They are mainly nocturnal, highly agile and arboreal
and can be seen foraging at dusk in the late spring and summer.
Global Distribution
A native of the Indian sub-continent, the Alexandrine Rat was historically introduced as an unsuspecting
passenger on sailing ships around the world and can now be found in all temperate and tropical coun-
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tries of the world.
Local Distribution
Generally found around Gibraltar outside urban areas in well vegetated zones, with denser populations
associated where food availability is greater, in particular the refuse compound at Hole in the Wall, Barbary
Macaque feeding areas on the Upper Rock, tourist sites, and Feral Cat feeding points.
Threat
The Black Rat has directly caused or contributed to the extinction of many species of wildlife including
birds, small mammals, invertebrates and plants, especially on small islands. The Alexandrine Rat is included
in the World Conservation Union’s (IUCN) 100 world’s worst invaders.
Small populations of this species in Gibraltar pose no threat to biodiversity. However on occasions, due
to a substantial food source, breeding success is increased and populations can explode. In such cases
infestations result that affect human habitation and property, as is the case at the tourist sites of Jew’s Gate,
St. Michael’s Cave and the Upper Galleries. It can also affect the natural environment with predation on
breeding birds and their chicks. R. r. alexandrinus has also been known to strip bare the cones of pine
trees (Pinus spp.) in search of pine nuts, depleting the natural seeding capability of this species.
In the past infestations have been addressed by the Environmental Health Department, now the
Environmental Agency, who have used rodenticide posions to control the species. This practice is indiscriminate
and poison can be ingested by other animals. This is totally unacceptable within a Nature
Reserve. Furthermore, the rat is a prime prey item of many raptors and owl species that would die if they
ingested poisoned rats.
Action
Rat infestations in Gibraltar should be tackled in an environmental friendly manner using non-toxic products
and methods. At the moment the main chemicals used against rodents are anticoagulant rodenticides,
which inhibit the vitamin-K cycle, preventing blood clotting and causing death from internal bleeding.
Warfarin, difenacoum and bromadiolone are now the most widely used chemical compounds in rodenticides.
These can be dangerous to humans (particularly children) and when used in suburban areas and
the Nature Reserve can impact non-target species. Mammals such as rabbits are just as likely to ingest
the cereal-based bait. Anticoagulants have long biological half-lives, so predators may be especially vulnerable
as residues from each contaminated prey item accumulate in the liver.
Environmentally friendly control methods, only targeting the pest species should be used. Amongst
these methods are:
• Live-trapping cages.
• Glue boards.
• Non-toxic baits.
Live trapping cages come in several forms that will trap single or multiple numbers of the target species.
Baited glue boards will attract a number of individuals that will become stuck, struggle and eventually die.
These two methods will require regular monitoring to eliminate the contents, but will provide an insight into
the extent of the infestation.
Non-toxic baits, in particular EradiRat®, contain no poisonous chemicals and are based on ground
maize combined with wheat and a sweet molasses attractant that will obstruct the digestive system and kill
the pest without posing a threat to its predators. The product ensures that there is:
• no risk to children or pets.
• no risk to livestock or pets.
• no risk of either primary or secondary poisoning, i.e., predator-friendly.
• no known resistance.
• no special needs for transport, handling storage or disposal.
• No risk of contamination to crops or food
• No risk of environmental pollution – fully biodegradable.
This product can be used virtually anywhere without any danger to the public and the environment and
does not require monitoring, for the rat will retreat and die in its burrow and the remaining unconsumed bait
is fully biodegradable (Ilex Organics Ltd).

Alien, Invasive & Pest Species
The product is recommended by the Barn Owl Trust of the United Kingdom and is approved by the UK
Health and Safety Executive under The Control of Pesticides Regulations 1986.
Further Reading:
• Major, H. L., & Jones, I. L., (2002) Impacts in the Norway Rat on the Auklet breeding colony at Sirius
Point, Alaska in 2002.
• Olkowski, W., Daar, S. and Olkowski, H., Taunton Press, (1991) Common-Sense Pest Control:
Least-toxic solutions for your home, garden, pets and community. Rats: 626-637., Mice: 287-294.
Class: Mammalia Order: Carnivora Family: Felidae
FERAL CAT
Felis catus
Figure 36: Feral cats feeding outside St. Michael’s Cave.
General Description
Feral cats are the 'wild' offspring of domestic cats that have strayed and settled in the wild, and are primarily
the result of pet owners' abandonment or failure to spay and neuter their animals, allowing them to
breed uncontrolled. A breeding pair can rear two or more litters a year.
Global Distribution
Cats were introduced to most parts of the world with the first European settlers, travelling as pets on
board ships and escaping to establish feral populations. Many islands in the Pacific, including the
Galapagos have been plagued by the species. They are also found on the mainland of Australia and New
Zealand, North America, Europe, Asia and Africa.
Local Distribution
Found everywhere in Gibraltar, with population hotspots around the North Mole, North Front Cemetery,
the east side reclamation area and Catalan Bay opposite the Caleta Hotel, Sandy Bay, Camp Bay, Little
Bay, the Alameda Gardens and within the Upper Rock Nature Reserve in the vicinity of St. Michael’s Cave,
the Cable Car top station and the Great Siege Tunnels.
Threat
The feral cat problem was aggravated by the disbanding of the cat and dog control unit of the Gibraltar
Government’s Environmental Health Department when this entity was privatised. Since then, cat infestations
are only tackled when there is a potential or existing human health implication. Cats are then trapped
and exterminated.
The problem is further compounded by well-wishing members of the public who constantly feed these
feral cats at locations including those mentioned above. The establishment of the Cat Welfare Society, who
undertook to rescue abandoned cats back in the late 1990s, was a respite, but the numbers escalated to
unmanageable proportions. In the early 2000s the Society established a programme to spay and neuter
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the wild feral population in collaboration with the Veterinary Clinic. This effort to control the rising population
is to be applauded, but many individual feral cats were not trapped and litters of kittens have frequently
been seen in most of the problem locations. It did not stem the existing large population of feral cats and
despite their efforts a culling programme is inevitable.
The Feral Cat is responsible for more species extinctions worldwide than any other animal, with the
exception of man. It is included in the World Conservation Union’s (IUCN) list of 100 world’s worst invaders
and has a terrible impact on wildlife. Cats are totally carnivorous, preferring to take live vertebrate prey
such as mammals, lizards, and snakes and preying extensively on landbirds.
Home ranges of feral cats searching for food are quite extensive (Fitzgerald & Karl, 1986) and they have
been seen everywhere within the Upper Rock Nature Reserve and well away from the traditional feeding
areas. Indeed, in recent years feral cats have become widely visible on nocturnal visits to the Nature
Reserve when carrying out nightjar and owl surveys, and have been seen taking wild birds, including
migrants (pers. obs.).
Populations of the Barbary Partridge and Rabbit are at risk and are easy targets for these animals.
Action
A Feral Cat control programme needs to be established as a priority. In particular, the populations within
the Upper Rock Nature Reserve need to be eliminated. It is totally unacceptable to have resident populations
of feral cats within the Nature Reserve. A control programme should include the following:
• Identify the feral cat population hotspots.
• Establish control procedures using live trapping with cages or leg-hold traps.
• Engage the collaboration of the Veterinary Clinic to put down the animals humanely.
• Establish an eradication programme for the Upper Rock Nature Reserve.
• Outlaw the feeding of Feral Cats in public areas.
• Outlaw the release of pet cats into the wild.
• Public awareness campaign on the Feral Cat problem.
This should be followed by constant monitoring of all affected areas in Gibraltar, to ensure that Feral
Cat populations remain under control.
Further Reading:
• Animal Welfare Advisory Committee (NSW) (1993) position paper for the control of cats in Australia
(unpublished).
• Dards, J.L. (1979) The population ecology of feral cats (Felis catus L.) in Portsmouth Dockyard.
Unpublished Ph.D. thesis, University of Bradford.
Class: Mammalia Order: Artiodactyla Family: Bovidae
FERAL GOAT
Capra hircus
Figure 38: Feral goats foraging on a hillside in Morocco. (J. Cortes).

Alien, Invasive & Pest Species
General Description
Males of this species are large animals, weighing around 45-55kg. They sport a strong set of spiral
horns with an anterior keel, and are bearded and have a strong smell during the breeding season. Females
are smaller and weigh approximately 25-35 kg. Both are variable in coloration with black and brown, straggly,
patterned, hairy coats.
Global Distribution
Most likely descended from Capra aegagrus from Central Asia. Since the domestication of the species,
goats have been introduced to all continents except Antarctica, and to many offshore islands.
Local Distribution
Imported illegally as a small herd of approximately 10 animals that roamed the Lower Slopes behind the
Calpe area, Feral Goats can now be found in two separate herds; one that roams around the Rock Gun
and Middle Hill area numbering around 15 individuals and another frequenting the area of Royal Anglian
Way and below the Ape’s Den, numbering around 20 individuals.
Threat
Goats have been recognised as being the single most destructive herbivore introduced to islands in the
world (King, 1985). The introduction of goats has resulted in severe impacts from overgrazing, often leading
to ecosystem degradation and biodiversity loss (Coblentz, 1978; Schofield, 1989; Moran 1996;
Descender et al. 1999). Goats roam about in groups that can build up to large herds.
In Gibraltar the goats are having a negative impact on the indigenous flora severely overgrazing native
herbs, grasses, trees and shrubs, and causing extensive erosion around the cliff areas of Royal Anglian
Way, below the Apes Den and the Rock Gun area. These can lead to rockfalls.
The Feral Goat must be eliminated from Gibraltar.
Action
The establishment of an eradication programme for the elimination of the feral Goat is an urgent priority.
There are several methods that can be applied to eliminate goats amongst which are:
• Shooting the herds in designated safe areas.
• Trapping the herds in wet weather in shelters.
• Setting noose traps.
Shooting can only be carried out under licence and with the permission and approval of the authorities
in compliance with health and safety regulations, in areas that are designated safe and at an hour of the
day, preferably dawn and early morning, when there will be less likelihood of human presence. GONHS
has already investigated this possibility and has sought and received approval for the culling of the species
using this method.
The trapping of goats utilising wire nooses set along the goats’ pathways is also a feasible method. The
traps would need to be frequently inspected to dispose of any animals caught.
Goats seek shelter in wet weather. They have been known to use some of the old gun batteries in Royal
Anglian Way in adverse weather conditions and could be trapped within these.
In drought conditions goats tend to drink more and stay closer to water. This behaviour could prove
useful when locating and trapping or culling the species, as they would frequent the Macaque watering
sites.
Further Reading:
• Clarke, G. M., (2000) Environmental pest species in Australia. Internal report. Department of the
Environment and Heritage, Canberra.
• Coblentz, B.E. (1978) The effects of feral goats (Capra hircus) on island ecosystems. Biological
Conservation, 13: 279-286.
• Coblentz, B.E. (1980) Effects of feral goats on the Santa Catalina Island ecosystem. In: D.M. Power
(Ed.) The California Islands: Proceedings of a Multidisciplinary Symposium, pp. 167-170. Santa
Barbara Museum of Natural History, Santa Barbara.
• Coleman, J., (1995) Baits and Baiting Strategies for Goats, Pigs and Cats. Science for Conservation
II. Department of Conservation, Wellington.
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• Descender, K., Baert, L., Maelfait, J., & Verdyck, P., (1999) Conservation on Volcan Alcedo
(Galapagos): Terrestrial invertebrates and the impact of introduced feral goats. Biological
Conservation, 87: 303-310.
• Moran, R.V. (1996) The flora of Guadaloupe Island, Mexico. Memoirs of the California Academy of
Sciences 19, California Academy of Sciences, San Francisco, CA.
• Schofield, E. K., (1989) Effects of introduced plants and animals on island vegetation: Examples from
the Galapagos Archipelago. Conservation Biology, 3: 227-238.
Class: Aves Order: Columbiformes Family: Columbidae
FERAL PIGEON
Columba livia (domest.)
Figure 37: Feral Pigeon Columba livia in the town area.
General Description
Feral pigeons are the domesticated descendants of the wild Rock Dove, Columba livia. The Rock Dove
is a plump grey bird with black wing-bars and a white rump or lower back. It has a red iris and a purple
breast with green sheen on the sides of the neck. Domesticated pigeons occur in a variety of colours.
Domestication has led to a high annual reproductive success, sometimes breeding throughout the year, and
pigeon feeding has led to the huge success of the species in our towns and cities.
Global Distribution
A cosmopolitan species that can be found worldwide close to human habitation.
Local Distribution
Feral pigeons have increased in Gibraltar in the last 20 years as the result of an upsurge in the keeping
of these domesticated birds in captivity. There were always small pigeon coops in Catalan Bay, the
Moorish Castle Estate and the Upper Town bordering the Lower Slopes where many chicken coops were
also kept. As a result many escaped domesticated pigeons have begun breeding in recesses, lofts, church
towers and tall buildings all over the town area. They have also invaded and taken over the traditional cliff
nesting sites of sensitive species of birds like the endangered Lesser Kestrel and the Little Owl.
Found mainly around the town area and in the south district residential areas, the Feral pigeon has also
become established on the North Face of the Rock and the east side cliffs above Camp Bay.
Threat
There is an excellent but shocking quote taken from the Tamside Council website information sheet on
the Feral Pigeon that states that ‘Pigeons carry significantly more diseases that are harmful to humans than
rats, and yet we wouldn't think of feeding a rat’.
The biggest threat of close contact with the Feral Pigeon comes from the implications of the avian
influenza virus H5N1 being contracted by these birds and transmitted to humans. In 2002 a dead Feral
Pigeon was discovered with the H5N1 virus (Ellis et al. 2004), and allegedly hundreds of dead pigeons in
Thailand were found to have HPAI H5N1 (Anon 2004, FAO 2005). However, with only two recorded
instances of infection and only one confirmation of the disease, the Feral Pigeon cannot be considered as
a serious threat to human health for the moment (Feare, 2005).

Alien, Invasive & Pest Species
There are also other threats that feral pigeons can bring:
• Health threat, including 40 diseases that can be passed onto humans.
• Potential diseases that can be transmitted to wild birds.
• Damage to structures, buildings and heritage through constant fouling with droppings.
• Invading and taking over nesting sites of wild bird species, including Little Owl, Lesser Kestrel,
Common and Pallid Swifts and House Sparrows.
• Soiling and nitrification of areas around nest sites affecting indigenous flora.
It is obvious that the impact of the Feral Pigeon on Gibraltar’s biodiversity is serious. Already, known
nesting sites of the Little Owl in recesses in the Tower of Homage were lost in the late 1980s due to a
takeover by this pest species. In the 1990s, as the population of the pigeons grew, nesting sites of the
Lesser Kestrel on the North Face cliffs of the Rock were occupied by this species. Partly as a result of this
the Lesser Kestrel, an endangered species for which a species action plan is included, declined substantially.
Crevices on the east side cliffs, potential nesting sites for the Little Owl, have also been occupied.
The problem will continue to escalate as long as the feeding of these birds continues. The problem is
a sociocultural one, for as long as the pigeon feeders continue their practice, the population growth of this
pest species will continue unabated. The authorities are worried about this problem as members of the
public have already expressed their concern in several letters in the press.
Due to the spread of the avian influenza virus to Europe, the Feral Pigeon has been identified by the
Avian Flu Civil Contingencies Committee as an urgent target. If the H5N1 virus increases its host range to
include passerines, pigeons and game birds, then activities such as cage bird shows, racing pigeons and
keeping pigeons will need to be evaluated (Feare, 2005).
Action
Several factors need to be taken into account when addressing the methods and criteria for the control
and management of this pest species, amongst which are:
• Assessment of the problem, through the identification of nesting and roosting sites.
• Targeting of those sites identified with a series of protection and eradication methods.
• Targeting the problem outside the breeding season of wild birds.
• Preventing access to recesses in buildings with netting.
• Protecting ledges with specially designed spike strips or sloping ledges.
• Preventing access to food.
• Outlawing the feeding of the species in public places.
• A public awareness campaign of the dangers and health hazard of this pest.
The use of poisoned or stupefying baits is totally unacceptable as this is an indiscriminate method that
can be ingested by wild bird species and other animals as well.
A cull of pigeons began in early 2006 in an attempt to reduce the threat of avian influenza were it to
arrive in Gibraltar. There was considerable success in the first few months. Subsequently the difficulty in
accessing pigeons at nesting or roosting sites (as opposed to feeding areas where they are trapped), and
the continuation of feeding by the public reduced the rate of decrease. Culling has proved an ineffective
method in many parts of the world (Haag-Wackernagel, 1992), for the population is soon re-established and
exceeded after a short time as breeding pairs are quickly replaced by young birds. In isolated areas, however,
where culling has been accompanied by a cessation of feeding, the method has been successful.
Breeding success is related to food availability, and pigeons can rear up to 10 chicks a year with an
abundant food supply. Reducing that supply will result in a lower breeding success rate and even failure.
It is important that legislation banning feeding of pigeons be enacted and enforced.
Ultimately the most successful control method will be a serious public awareness campaign together
with a restriction or total ban on the feeding of pigeons, accompanied with culling.
Further Reading:
• Feare, C. J., (2005) Conservation Implications of Avian Influenza. RSBP Report No. 14.
• Haag-Wackernagel, D., (1992) Regulation of the street pigeon in Basel.
• Haag-Wackernagel D, Spiewak R. (2004) Human infestation by pigeon fleas (Ceratophyllus columbae)
from feral pigeons. Ann Agric Environ Med; 11: 343-346.
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Class: Aves Order: Charadriiformes Family: Laridae
YELLOW-LEGGED GULL
Larus michahellis
Figure 39: An adult Yellow-legged Gull Larus michahellis. (C. Perez)
General Description
Once considered a subspecies of the Herring Gull Larus argentatus, the Yellow-legged Gull is actually
a closer relative of the Lesser-blacked Gull Larus fuscus, and has been given full species status. The
Yellow-legged Gull is a large white gull with a pale grey back and mantle and black tips to the wing. Their
legs are yellow, differentiating them from similar sized species with pink legs. The iris is yellow with a red
orbital ring and the bill is strong and heavy, coloured orange yellow with an extensive red spot near the tip
of the lower mandible. Juveniles and immatures are mottled brownish and do not attain full adult plumage
until their fourth year. Breeding takes place in the spring, with nests located mainly on cliffs and open
ground. Adults rear a clutch of three birds on average. Chicks are mainly fed on fish, but outside the breeding
season the species feeds on eggs, birds, fish, and carrion and is often seen at refuse tips. The birds
depart at the end of the breeding season in mid July, and disperse north and south along the Atlantic coast
and north up the Mediterranean coast, returning in early October.
Global Distribution
Mainly found in the western Mediterranean basin and the Atlantic coast of Iberia.
Local Distribution
Not recorded as breeding by Irby (1876), the bird was confirmed as breeding by Rait-Kerr in 1934
(Cortes et al. 2004). It is now found extensively in all habitats, including urban areas, and is Gibraltar’s
most common bird.
Threat
Irby had not recorded the bird as breeding but it must surely have been present as a scavenger in the
port area and surrounding waters of the Bay and Strait. In the early 1970s several hundred pairs were
recorded, breeding mainly on the upper reaches of the Rock. Since then the increased human activity and
population expansion that has taken place in the hinterland, increased commercial fishing activity in the
ports of Algeciras and La Linea and the growing number of refuse tips have resulted in a population explosion
of this species to pest proportions.
These numbers are affecting the local biodiversity and having an effect on the ecosystem as a whole in
Gibraltar. They also harass birds of prey on migration, in particular Griffon Vultures Gyps fulvus and Shorttoed
Eagles Circaetus gallicus, and occasionally drive them into the sea where they drown. Local nesting
birds also suffer from the continual harassment of the Gulls, which tend to take over all suitable nesting
sites.

Alien, Invasive & Pest Species
The native flora is also affected in various ways. Nesting sites are located on open ground and cliff
ledges, a habitat that is preferred by many of Gibraltar’s rare species of plant. Nesting material is composed
of small tufts of grass and plants that are ripped out by the gulls. The guano of the gulls around the
main nesting areas is thought to be changing the pH and nitrifying the soil, increasing the colonisation capability
of other plants to the detriment of many of the rare native species adapted to local conditions.
Gull infestation has also had a negative effect on humans through the soiling of structures, buildings,
cars and clothes on washing lines, and nesting of the species in urban areas on roofs and balconies. They
attack people during the nesting season and while they rarely cause injury, their aggression can cause fright
and even panic.
Action
A comprehensive history and analysis of the Gull Cull situation can be found in Perez & Bensusan
(2005), and suggests that there is a need to analyse the gull cull strategy of the last decade in order to prepare
the ground for the next 10 years.
This analysis is mainly based on the paper by Cortes et al. (2004) ‘The Control of the Yellow-legged
Gull in Gibraltar’, which deals with the matter more thoroughly.
The present Gull Cull contract has been successful initially in reducing the rate of increase of the population
and currently in maintaining the present population stable. Amongst the recommendations that will
improve the present situations are:
• An increase in the manpower of the Gull Cull Unit, especially during the breeding season.
• Specific targeting of adult birds.
• Tackle the removal of nests in urban areas separately, as this takes considerable effort for little return,
although receiving public appreciation and support.
• Increase disturbance at breeding sites through the use of raptors of the Bird Rehabilitation Unit.
• Increasingly utilise the resources of the Cliffs and Caves section of GONHS to tackle inaccessible
areas.
• Apply the fox re-introduction programme to other localities of the Upper Rock, including the Great Sand
Slopes, Lower Slopes and Northern Defences area.
A reduction of available feeding sites would drastically reduce the population and breeding success of
the gulls. However, unlike the Feral Pigeon, control of feeding sites of this species is virtually impossible
since they forage far afield in rubbish tips many miles away, returning to the Rock in the evenings. Securing
rubbish deposition areas to prevent the gulls ripping plastic bags open, ensuring that school playgrounds
are left clean after playtime, and any other food access prevention methods would certainly improve the situation,
and reduce aggression of this species towards humans.
Finally, because of the wide-ranging habits of the species, measures in Gibraltar should form part of a
wider regional strategy.
Further Reading:
• Cortes, J. C., Shaw, E., Blair, M., Candelin, G., (2003) The Control of the Yellow-legged Gull, Larus
michahellis, in Gibraltar. Almoriama. 31. pp199-216.
• GOS (1980) Report on Herring Gull Cull at Gibraltar. Spring 1980. Gibraltar: Gibraltar Ornithological
Society.
• Irby, L. H. (1895) The Ornithology of the Straits of Gibraltar, 2nd Ed. London: Taylor & Francis.
• Perez, C. E. & Bensusan, K. E. (2005) Upper Rock Nature Reserve. A Management and Action Plan.
The Yellow-legged Gull. pp177-179. The Gibraltar Ornithological & Natural History Society.
Gibraltar.
• Vidal E., Bonnet V. (1997) Use of nest materials by Yellow-legged Gull. Consequences on vegetation
of their colonies. Alauda, 65: 301-305
• Vidal E., Medail F., Tatoni T., Bonnet V. (2000) Seabirds drive plant species turnover on small
Mediterranean islands at the expense of native taxa. Oecologia, 122: 427-434.
• Vidal E., Roche P., Bonnet V., Mante A. (2000) Habitats selection and nest density distribution in a
colony of Yellow-legged Gull Larus cachinnans. Proceedings of Medmaravis, Malta: Monitoring
and conservation of Birds, Mammals and Sea Turtles of the Mediterranean and Black Seas, 124-
132.
• Vidal E., Roche P., Bonnet V., Tatoni T. (2001) Nest-density distribution patterns in a large Yellowlegged
gull colony. Acta Oecologica, 22: 245-251.
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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References & Glossary
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Biodiversity Action Plan, Gibraltar: Planning for Nature
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Glossary
ACCOBAMS Agreement on the Conservation of Cetaceans of the Black Sea,
Mediterranean Sea and contiguous Atlantic area
Bern Convention Convention on the Conservation of European Wildlife and Natural Habitats.
Biodiversity Convention The Rio de Janeiro Convention on Biological Diversity 93/626/EEC also
known as the CBD
Bonn Convention Convention on the Conservation of Migratory Species of Wild Animals
82/461/EEC also known as CMS.
CBD Convention on Biological Diversity
CITES The Convention on the Trade in Endangered Species of Wild Flora and
Fauna
CMS Convention on the Conservation of Migratory Species of Wild Animals
CoP Conference of Parties
cSAC Candidate Special Area of Conservation
DEFRA Department for Environment, Food and Rural Affairs
DPC Development and Planning Commission
EEA European Environmental Agency
EEC European Economic Community
EC Birds Directive Council Directive 79/409/EEC on the Conservation of Wild Birds
EC Habitats Directive Council Directive 92/43/EEC on the Conservation of Natural Habitats and
of Wild Fauna and Flora
EIA Environmental Impact Assessment
EMAS the Eco-Management and Audit Scheme
Emerald Network Areas of Special Conservation Interest' set up by Council of Europe under
Bern Convention
EU European Union
EUROBATS The Agreement on the Conservation of Populations of European Bats
GISP Global Invasive Species Programme
GONHS Gibraltar Ornithological & Natural History Society
GTI Global Taxonomy Initiative
HMSO Her Majesty's Stationary Office
IBAs Important Bird Areas
IPCC Intergovernmental Panel on Climate Change
IUCN World Conservation Union
JNCC Joint Nature Conservancy Council
L/N Legal Notice
MEAs Multilateral Environmental Agreements
MoD Ministry of Defence
Natura 2000 European Union-wide network of nature conservation sites established
under the Habitats Directive.
NGO's Non-governmental Organisations
OTA United States Office of Technology Assessment
SAC/SaC Special Area of Conservation
SPA Special Protection Area
SPEC Species of European Conservation Concern
World Heritage Convention The Convention concerning the Protection of the World Cultural and
Natural Heritage