Polar Biology

, Volume 42, Issue 8, pp 1581–1593 | Cite as

Space use patterns affect stable isotopes of polar bears (Ursus maritimus) in the Beaufort Sea

  • Nicole P. BoucherEmail author
  • Andrew E. Derocher
  • Evan S. Richardson
Original Paper


Space use patterns vary within a population and can influence diet composition of individuals. Within the Beaufort Sea, polar bears (Ursus maritimus) either use offshore areas and follow sea ice retreat (pelagic) or utilize nearshore areas (coastal), exposing individuals to different food sources. We examine the relationship between coastal and pelagic space use patterns and diet quantified by stable isotopes (δ15N and δ13C) of polar bears in the Beaufort Sea between 2007 and 2011. We examined spatial fidelity using home range overlap and assigned bears to one of two space use patterns (coastal or pelagic) based on proximity of home ranges to the coast. We estimated diet composition using inter- and intratissue variability in stable isotopes from hair and claws to examine seasonal shifts in diet. Sectioning of claws provided additional insights on diet, but guard hair sections did not. Polar bears showed spatial fidelity between years. Nitrogen stable isotopes were related to space use patterns. Coastal bears were 15N-depleted compared to pelagic bears due to coastal bears being enriched in 15N possibly from either scavenging on bowhead whale carcasses (Balaena mysticetus) killed during subsistence hunts or pelagic bears being nutritionally stressed. Although upper trophic level predators can provide insight into trophic dynamics and changes in ecosystem function, knowledge of space use patterns and foraging behavior is an important aspect of diet interpretation.


Space use Stable isotopes Beaufort sea Polar bears Ursus maritimus 



We gratefully acknowledge support from Banrock Station Environmental Fund, Canadian Association of Zoos and Aquariums, Canadian Wildlife Federation, Environment and Climate Change Canada, Hauser Bears, Natural Sciences and Engineering Research Council of Canada, Polar Bears International, Polar Continental Shelf Project of Natural Resources Canada, Quark Expeditions Ltd., United States Department of the Interior (Bureau of Ocean Energy Management), Kansas City Zoo, and World Wildlife Fund Canada.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflicts of interest to disclose.

Human and animal rights

All applicable international, national, and/or institutional guidelines for the care and use of animals were followed.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Biological SciencesUniversity of AlbertaEdmontonCanada
  2. 2.Wildlife Research Division, Science and Technology BranchEnvironment and Climate Change CanadaWinnipegCanada

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