Seasonal habitat selection by adult female polar bears in western Hudson Bay

• Published in: Population Ecology
• Main Authors: McCall, Alysa G., Pilfold, Nicholas W., Derocher, Andrew E., Lunn, Nicholas J.
• Other Authors: ArcticNet, Canadian Wildlife Federation, Environment Canada, Natural Sciences and Engineering Research Council of Canada, Quark Expeditions, University of Alberta, W. Garfield Weston Foundation, World Wildlife Fund (Canada and International), ArcticNet (CA), Polar Bears International, Canadian Association of Zoos and Aquariums, Aquarium du Quebec, Canadian Wildlife Federation (CA), Canadian Circumpolar Institute's Boreal Alberta Research Grant, Care for the Wildlife International, Environment Canada (CA), Hauser Bears, Isdell Family Foundation, Manitoba Conservation, Natural Sciences and Engineering Research Council of Canada (CA), Northern Scientific Training Program of Aboriginal Affairs and Northern Development Canada, Parks Canada Agency, Polar Continental Shelf Project, Wildlife Media Inc., W. Garfield Weston Foundation (CA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: Ecology, Evolution, Behavior and Systematics; Hudson Bay; Hudson; Sea ice; Ursus maritimus
• Online Access: http://dx.doi.org/10.1007/s10144-016-0549-y; http://link.springer.com/content/pdf/10.1007/s10144-016-0549-y.pdf; http://link.springer.com/article/10.1007/s10144-016-0549-y/fulltext.html; http://link.springer.com/content/pdf/10.1007/s10144-016-0549-y

Abstract Individual variation in habitat selection has emerged as an important component necessary for understanding population ecology. For threatened species, where habitat loss and alteration affect population trends, understanding habitat use provides insight into mechanisms of population change. Polar bears, Ursus maritimus , in the Western Hudson Bay subpopulation have experienced declines in body condition, survival, and abundance associated with delayed freeze‐up and earlier break‐up of sea ice due to climate change. Although this subpopulation has been intensively studied, sea ice habitat selection remains poorly understood. We developed a habitat selection model using a mixed conditional logistic regression to determine habitat selection across seasons (freeze‐up, early winter, late winter, break‐up) and assess individual variation in habitat selection. We used 8487 locations collected between 2004 and 2010 from 64 GPS satellite linked radio‐collars on adult females to compare habitat selected to habitat available. Selection changed across seasons and varied the most among individuals during the freeze‐up and break‐up seasons. During later winter, there was less variation in habitat selection among individuals and bears showed the least amount of selection in habitat use. Distance to the denning area, a core terrestrial refuge habitat, was the top‐ranked covariate in all seasons suggesting site fidelity plays a role in habitat selection. Some individual variation may have been due to reproductive status, though we could not account for this directly. Recognizing individual differences, especially in a rapidly changing environment, allows managers to identify critical habitats instead of simply average resources, and may lead to more successful efforts to protect habitats.