130925-studie-wildlife-comeback-in-europe

Threat Description Impact
Human intrusions Human disturbance can result in desertion of High
and disturbance entire colonies or shifts in subsequent seasons.
Problematic
native species
Problematic
non-native/alien
species
Climate change
and severe
weather
Hunting and
collecting
Table 2.
Major threats that
drove Roseate tern
decline and may
still constrain the
population [2] .
Table 3.
Conservation actions
in place for Roseate
tern [2] .
Predation by Red foxes (Vulpes vulpes), Stoats
(Mustela erminea), hedgehogs, Black rats (Rattus
rattus), Peregrine falcons (Falco peregrinus) and
large gulls (Larus spp.).
Competition for nest sites with large gulls.
Predation by introduced mammals on the Azores
(Brown rats, Rattus norvegicus, Polecats, Mustela
putorius, Ferrets, M. putorius furo) or elsewhere
in Europe American mink (Neovison vison) and
Brown rats.
Bad weather can reduce food availability and
affect chick survival and growth rate.
Winter storms washed away a major breeding
site in Ireland in the mid-1970s, while increased
frequency of summer storms threatens another
Irish site. Sea level rise may exacerbate the scale
of the problem.
Food shortage in winter due to declining fish
stocks, potentially driven by long-term changes in
sea-surface temperature.
Trapping on wintering grounds in West Africa.
High
Low/Medium
High
Unknown
Low/Medium
Unknown
Unknown,
potentially high
Action Description Impact
Monitoring and Species Action Plan in place.
Medium/high
planning
Most major breeding colonies are regularly
monitored.
High
Site/area
protection
Site/area
management
There are 53 IBAs identified for Roseate tern in
Europe, of which 45% are fully designated as SPAs
or other protected areas, including most breeding
colonies and the main foraging sea area around
Rockabill, and 8% are not protected.
Wardening of breeding colonies, particularly in
the UK, Ireland and France.
Habitat management to create suitable terraces
and vegetation.
Medium/high
High
High
Species recovery Nest box provision in Ireland, the UK and France. High
Invasive/
problematic
species control
Education and
awareness
Legislation
recent observations, suggesting that the species
is either very rare or locally extinct [3, 10, 21] . Small
numbers have bred in the Camargue in southern
France, as well as northwest Germany, Belgium and
possibly Denmark, though often in mixed-species
pairs [2, 4, 17, 20] .
In the Azores, Roseate terns have bred on all
nine islands of the archipelago, and have used
49 sites, of which breeding has been consistent
at only five (two colonies on Flores, and single
colonies on Graciosa, Terceira and Santa Maria;
Figure 2) [3] . Roseate terns were exterminated in
Ireland and nearly disappeared from Britain in
the 19th century, but the species recovered and
recolonised Ireland in 1913 [4, 20] . The main colony
in Ireland is Rockabill, on the east coast, followed
Control of American mink in France and rats in
the UK and Ireland.
Awareness raising campaign in Ghana and
Senegal to reduce trapping in winter.
Fully protected by the Law and included in a
number of international treaties (see ‘Legal
protection and conservation status’).
High
Unknown
High
by Lady’s Island Lake in the southeast [10] . In
Britain, the main breeding sites are in Anglesey
(Wales) and on Coquet Island in northeast
England [10] .
Major threats
Persecution for the millinery trade drove Roseate
terns close to extinction in Europe in the 19th
century [4] . The species always had a very restricted
range compared to other tern species, as it requires
islands with low predation close to high densities
of prey [17] . Currently, the Roseate tern population
in Europe is limited by factors that affect the
number and quality of suitable colony sites [3] . This
is because Roseate terns have relatively low adult
survival rates [22] and high productivity is essential
for population stability [23] .
The main reasons for the Roseate tern decline
in Europe during the 1960s and 1970s relate to the
conditions at the breeding colonies, mainly the
loss of the colony at Tern Island in Ireland due to
storms, as well as a shortage of food in the wintering
grounds in Africa and persecution [1, 2, 4, 10, 24] . In Europe
during this period, increasing Herring gull (Larus
argentatus) and other gull populations resulted in
increased competition and also predation, while
human disturbance also increased through the
development of recreational activities, which facilitates
predation [2, 10, 23, 24] .
Currently, predation by mink and Peregrine
falcons is one of the main reasons for destabilisation
of colonies [1, 23, 25] , while erosion of breeding
sites is a potential threat for the long-term viability
of colonies [2, 10] . Trapping in the wintering grounds
is an ongoing threat, indicated by a resurgence of
trapping activity recorded recently in Ghana [3] .
Drivers of recovery
Following dramatic declines in the 19th century,
Roseate terns recovered thanks to protective legislation
that banned hunting of the species [4] . After
the more recent declines of the 1960s and 1970s,
the species recovered thanks to targeted conservation
actions, including control of predators,
protection of breeding sites and provision of nest
boxes to improve colony productivity and size.
Management on Rockabill has contributed to
enhanced productivity of the colony compared to
other sites, an the site benefits from much higher
food availability and inaccessibility to predators
thanks to its large distance offshore [3, 17, 24, 26] .
Education and awareness raising campaigns were
also carried out, particularly in West Africa [10] .
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