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Marine Biology Commons

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Biochemistry, Biophysics, and Structural Biology

2023

Polar bear

Articles 1 - 2 of 2

Full-Text Articles in Marine Biology

A Colonial-Nesting Seabird Shows Limited Heart Rate Responses To Natural Variation In Threats Of Polar Bears, Erica A. Geldart, Oliver P. Love, Andrew F. Barnas, Christopher M. Harris, H. Grant Gilchrist, Christina A.D. Semeniuk Oct 2023

A Colonial-Nesting Seabird Shows Limited Heart Rate Responses To Natural Variation In Threats Of Polar Bears, Erica A. Geldart, Oliver P. Love, Andrew F. Barnas, Christopher M. Harris, H. Grant Gilchrist, Christina A.D. Semeniuk

Great Lakes Institute for Environmental Research Publications

Several predator-prey systems are in flux as an indirect result of climate change. In the Arctic, earlier sea-ice loss is driving polar bears (Ursus maritimus) onto land when many colonial nesting seabirds are breeding. The result is a higher threat of nest predation for birds with potential limited ability to respond. We quantified heart rate change in a large common eider (Somateria mollissima) breeding colony in the Canadian Arctic to explore their adaptive capacity to keep pace with the increasing risk of egg predation by polar bears. Eiders displayed on average higher heart rates from baseline when polar bears were …


Heightened Heart Rate But Similar Flight Responses To Evolved Versus Recent Predators In An Arctic Seabird, Erica A. Geldart, Oliver P. Love, H. Grant Gilchrist, Andrew F. Barnas, Christopher M. Harris, Christina A.D. Semeniuk Jun 2023

Heightened Heart Rate But Similar Flight Responses To Evolved Versus Recent Predators In An Arctic Seabird, Erica A. Geldart, Oliver P. Love, H. Grant Gilchrist, Andrew F. Barnas, Christopher M. Harris, Christina A.D. Semeniuk

Great Lakes Institute for Environmental Research Publications

Predator-prey dynamics in the Arctic are being altered with changing sea ice phenology. The increasing frequency of predation on colonial nesting seabirds and their eggs by the polar bear (Ursus maritimus) is a consequence of bears shifting to terrestrial food resources through a shortened seal-hunting season. We examined antipredator responses in a colony of nesting Common Eiders (Somateria mollissima) on East Bay Island, Nunavut, Canada, which is exposed to established nest predators, such as arctic fox (Vulpes lagopus), but also to recent increases in polar bear nest predation due to the bears’ lost on-ice hunting opportunities. Given eiders’ limited eco-evolutionary …