What to eat now? Shifts in polar bear diet during the ice-free season in western Hudson Bay
Article first published online: 28 AUG 2013
© 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
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Ecology and Evolution
Volume 3, Issue 10, pages 3509–3523, September 2013
How to Cite
Ecology and Evolution 2013; 3(10): 3509–3523
- Issue published online: 19 SEP 2013
- Article first published online: 28 AUG 2013
- Manuscript Accepted: 24 JUL 2013
- Manuscript Revised: 15 JUL 2013
- Manuscript Received: 27 MAY 2013
- Hudson Bay Project
- American Museum of Natural History. Grant Number: 0655
- Arctic Institute of North America
- Churchill Northern Studies Centre
- City University of New York
- Manitoba Conservation. Grant Number: 27070
- Climate change;
- polar bears;
- Ursus maritimus ;
- western Hudson Bay
Under current climate trends, spring ice breakup in Hudson Bay is advancing rapidly, leaving polar bears (Ursus maritimus) less time to hunt seals during the spring when they accumulate the majority of their annual fat reserves. For this reason, foods that polar bears consume during the ice-free season may become increasingly important in alleviating nutritional stress from lost seal hunting opportunities. Defining how the terrestrial diet might have changed since the onset of rapid climate change is an important step in understanding how polar bears may be reacting to climate change. We characterized the current terrestrial diet of polar bears in western Hudson Bay by evaluating the contents of passively sampled scat and comparing it to a similar study conducted 40 years ago. While the two terrestrial diets broadly overlap, polar bears currently appear to be exploiting increasingly abundant resources such as caribou (Rangifer tarandus) and snow geese (Chen caerulescens caerulescens) and newly available resources such as eggs. This opportunistic shift is similar to the diet mixing strategy common among other Arctic predators and bear species. We discuss whether the observed diet shift is solely a response to a nutritional stress or is an expression of plastic foraging behavior.