ABSTRACT
Surviving in the frigid Arctic through months of winter darkness and roaming vast areas over the frozen oceans, few species are as charismatic and photogenic as the polar bear (Ursus maritimus) (see Figure 14.1). Sitting at the top of the Arctic marine food web, polar bears provide insight on the status, health and functioning of marine ecosystems over a variety of spatial and temporal scales. Having evolved from a grizzly/brown bear (U. arctos) ancestor in a rapid burst of evolution (Waits et al, 1999), polar bears evolved a life history pattern dependent on the sea ice. With this specialization, numerous morphological and physiological adaptations followed. Four-month-old cubs snuggle up to their mother during research activities on the ecology of polar bears in the Beaufort Sea, Canada https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781849772679/cbb7f19a-b3ed-4b1d-92db-b60bfc8e168e/content/fig14_1_B.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/> Source:Photograph by A. E. Derocher.
