• Corpus ID: 86184243

Breeding skuas in Orkney: a 2010 census indicates density-dependent population change driven by both food supply and predation

  title={Breeding skuas in Orkney: a 2010 census indicates density-dependent population change driven by both food supply and predation},
  author={E. R. Meek and Mark Bolton and J. Remp},
Great Skuas Stercorarius skua and Arctic Skuas S. parasiticus were counted on their breeding grounds in Orkney during June 2010. Great Skua numbers had fallen by 23% overall since the previous census in 2000. However, the decline was not uniform across Orkney, the major colony on Hoy declining by 32% but with many smaller colonies actually increasing. Possible reasons for this difference are discussed. Arctic Skua numbers fell by 47% in the same time period and by 64% from their peak in 1992… 

Figures and Tables from this paper

The use of eggs and diet of great skuas as biomonitors in the Faroe Islands

It is suggested that there is some breeding benefits of specialising on bird predation, but the relationship does not appear to result in larger eggs in Faroese great skuas.

Combined bottom‐up and top‐down pressures drive catastrophic population declines of Arctic skuas in Scotland

Scotland's Arctic skua population is declining rapidly, with bottom-up and top-down pressures simultaneously reducing breeding success to unsustainably low levels, and this study demonstrates severe vulnerability of seabirds to rapid change in human-modified ecosystems.

Change in the North Sea ecosystem from the 1970s to the 2010s: great skua diets reflect changing forage fish, seabirds, and fisheries

Understanding anthropogenic impacts are crucial to maintain marine ecosystem health. The North Sea has changed in recent decades, largely due to commercial fishing and climate change. Seabirds can

Beyond climate envelopes: bio‐climate modelling accords with observed 25‐year changes in seabird populations of the British Isles

Climate influences the population sizes of multiple seabird species in the British Isles and highlights the potential for outputs of CEMs fitted with coarse resolution occupancy data to provide information on both local abundance and sensitivity to future climate changes.

OP-ICES180172 925..937

Gabriella E. Church, Robert W. Furness, Glen Tyler, Lucy Gilbert, and Stephen C. Votier* Centre for Life and Environmental Sciences, School of Biosciences, Environment & Sustainability Institute,

Investigating the potential effects of marine renewable energy developments on seabirds

27 2.



Interactions with Great Skuas Stercorarius skua as a factor in the long‐term decline of an Arctic Skua Stercorarius parasiticus population

This model suggests that both interspecific competition for territories with Great Skuas and food limitation have played important roles in the decline of Arctic Skua on Fetlar.

The effects of changes in food availability on the breeding ecology of great skuas Catharacta skua in Shetland

Changes in the age structure of the breeding population and the absence in 1989 of 28% of adults colour-ringed during incubation in 1988 suggest an increase in the rate of egress since the 1970s, which probably represents an increased in the long-term costs of reproduction to adults at this colony.

The effect of age and year on the survival of breeding adult Great Skuas Catharacta skua in Shetland

The survival rates of breeding adult Great Skuas Catharacta skua were examined at Foula, the largest colony in the world, where numbers have been declining since the late 1970s. Resightings of

The incidence of nonbreeding by adult great skuas and parasitic jaegers from Foula, Shetland

Evidence is presented that the decline in breeding frequency of old birds was due to senescence as opposed to increased frequency of mate-changes resulting from a high mortality of old partners.

The influence of food availability on the breeding effort and reproductive success of Arctic Skuas Stercorarius parasiticus

Territorial attendance, chick growth rate and breeding success of Arctic Skuas Stercorarius parasiticus in Shetland were lowest in the late 1980s when recruitment of Sandeels Am-modytes marinus in

The dispersal and philopatry of great skuas from foula, Shetland

Ring recovery data were used to describe the dispersal of Great Skuas from Foula, Shetland, from 1963 to 1990. In general, the dispersal patterns and causes of recoveries had not changed since they

Recruitment of lesser sandeel Ammodytes marinus in relation to density dependence and zooplankton composition

It is argued that early egg production in C. finmarchicus supports the survival of larvae, and that climate-generated shifts in the Calanus species composition lead to a mismatch in timing between food availability and the early life history of lesser sandeels.


It is suggested that the consequences of poor food availability are shared between offspring and parents in this species, and adult return rate is more sensitive to food availability than has been assumed previously.

A view from above : changing seas, seabirds and food sources

In this review we summarize what is known about mechanisms by which climate change may be affecting the populations of seabirds around the UK. Breeding success and adult survival are the key factors

Sandeel recruitment in the North Sea: demographic, climatic and trophic effects

A negative relationship was detected between recruitment and the winter index of the North Atlantic Oscillation, which affects sea temperatures during the egg and larval period, and the findings suggest that climate change may impact upon sandeel populations in the North Sea.