State of Nature report - RSPB

UK OVERSEAS TERRITORIES
The UK has 14 Overseas Territories (UKOTs), scattered
around the world, from Europe to the Caribbean, to the
South Atlantic. They include hundreds of small islands,
as well as the British Antarctic Territory, which has a land
area six times the size of the UK. The marine area under their
jurisdiction is immense, and includes pristine coral reefs as
well as the frozen seas of the Antarctic.
Our Overseas Territories are incredibly diverse socially,
economically, geographically and ecologically, but they are
home to a relatively small human population. For example,
the Pitcairn Islands support more endemic species than
their entire human population – there are 53 resident
Pitcairn Islanders and more than 70 endemic species. Local
communities are highly reliant on biodiversity for their
livelihoods and quality of life. Fisheries and nature tourism
underpin many Territories’ economies, mangroves and coral
reefs provide protection from hurricanes and rainforests help
guarantee freshwater supplies.
Outstanding importance
The UKOTs are home to an incredible array of species, from
elephant seals and penguins in the South Atlantic territories,
to iguanas and parrots in the Caribbean. Their outstanding
global importance for biodiversity dwarfs that of the UK
itself. At least 180 endemic species of plant (including many
endemic genera), 22 endemic birds, 34 endemic reptiles
and amphibians 1 and 685 endemic terrestrial invertebrates
have already been described in the Territories – 16 times the
number in the UK. However, there are gaps in our knowledge,
so many more endemic species could still lie undiscovered.
In addition to their many endemics, the Territories host
significant numbers of seabirds and other fauna, including a
third of the world’s breeding albatrosses. Their unique habitats
are internationally important, and include the world’s largest
and most pristine coral atoll – the Great Chagos Bank in the
British Indian Ocean Territory. There are 81 Important Bird
Areas (IBAs) recognised in the UKOTs 2 , and work has begun to
identify important areas for plants and other biodiversity.
Case study
Tackling non-native species
Invasive non-native species are a particular concern in the
UKOTs and tackling them is a key conservation priority.
To date, a number of projects have assessed the impacts
that particular introduced species have had on native wildlife
in the UKOTs. In some cases, the feasibility of eradication
projects has also been examined, although few eradications
have yet been attempted. Work is currently underway to
identify the most suitable islands and sites for vertebrate
eradication programmes across 11 of the UKOTs, with the
aim of producing a priority list for vertebrate eradications by
taking into account their benefits, feasibility and sustainability.
On Ascension Island in the South Atlantic, introduced cats had
caused the loss of millions of breeding seabirds since the 19th
century. The seabirds that remained were restricted to small
offshore stacks and ledges that cats could not reach. In 2002,
the RSPB began a project to eradicate feral cats and by 2006
the island was declared feral cat-free, making Ascension the
largest inhabited island to have been cleared of feral cats.
Since then, seabirds have begun to spread back onto the
main island, with species such as the masked and brown
booby, and brown noddy, responding particularly quickly 6 .
In December 2012, two pairs of the endemic Ascension
frigatebird were discovered nesting on the main island for
the first time in 180 years – an important milestone and
testament to the power of conservation.
Kevin Schafer (NHPA/Photoshot)
Under threat
Even with the limited knowledge that we have, it is clear
that much of the unique biodiversity of the UKOTs is under
severe threat: over 90 species are now classified as Critically
Endangered globally, compared with just four species in the
UK 3 . The last recorded global extinction in the UKOTs, of the
St Helena olive tree, occurred as recently as 2003 4 . However,
at present, few of the areas most important for biodiversity
in the UKOTs have any level of legal protection; development
and invasive species still threaten many sites.
We have only limited data on the threat status of many
species in the UKOTs. In Pitcairn 5 , work for the 2008 IUCN
Global Red List indicated that only 146 of 466 known species
had been assessed. Of these 146 species, one was Critically
Endangered, 10 were Endangered, and 31 were Vulnerable.
Fifteen of the species assessed were endemics and all of
these were globally threatened.
Ascension frigatebird
STATE OF NATURE 2013 67