Foraging Ecology

Winter can be hard

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Science  04 May 2018:
Vol. 360, Issue 6388, pp. 504-505
DOI: 10.1126/science.360.6388.504-a

Changes in climate affect the abundance of red-legged kittiwakes.


The largest breeding colony of the red-legged kittiwake, an Arctic seabird, has undergone drastic declines and recovery over the past 40 years. It has been assumed that these changes have been driven by climate-induced shifts in food supply during breeding. Will et al. examined feathers collected from living birds and museum specimens to characterize isotopic signatures (which give a picture of food intake) and corticosterone levels (which relate to stress) over a 100-year period. They found that birds were less stressed when oceanic conditions in the eastern Pacific were warmer in both summer and winter and when sea ice was less extensive in the winter. Further, during years with more extensive ice, nitrogen isotope levels were higher, potentially indicating a higher reliance on energy stores. These results suggest that climate variability can directly affect population size and persistence and that winter conditions are important to reproductive success.

Mar. Ecol. Prog. Ser. 10.3354/meps12509 (2018).

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