Thompson Rivers University

Environmental Sciences Seminar Series: Climate change and polar bears

Dr. Andy Derocher of the University of Alberta presents Climate change and polar bear life history vulnerabilities as part of the Environmental Sciences Seminar Series.

❏ More lectures in the ESS series

Abstract

Habitat loss is the major threat facing ursids across their range. In the Arctic, climate change has fundamentally altered and degraded polar bear (Ursus maritimus) habitat with projected changes predicted to result in population extirpations.

The effects of climate change on polar bears are well understood because they have a long history of research and monitoring. Climate change affects polar bear life history at several critical life history points.

Energy stores are the primary affected link and the key to understanding the effects of habitat loss lies in the balance between energy intake and energy use. Energy intake is mediated by the duration of ice cover, prey abundance, and prey vulnerability.

Energy use is influenced by growth, reproduction, and maintenance costs that are directly influenced by habitat conditions and ice-free period duration.

While polar bears are still abundant across the Arctic, their future is dependent on sea ice. I will review the ecology of polar bears within the context of climate change and explore why this species has become the “poster-species” for a warming world.