Polar Bear Maternity Denning in the Beaufort Sea

Abstract

The distribution of polar bears (Ursus maritimus) is circumpolar in the Northern Hemisphere, but known locations of maternal dens are concentrated in relatively few, widely scattered locations. Denning is either uncommon or unknown within gaps between known denning concentration areas. The Beaufort Sea region of Alaska and Canada lies in the largest of those gaps. To understand effects of industrial development and proposed increases in hunting, the temporal and spatial distribution of denning in the Beaufort Sea must be known. We captured and radiocollared polar bears between 1981 and 1991 and determined that denning in the Beaufort Sea region was sufficient to account for the estimated population there. Of 90 dens, 48 were on drifting pack ice, 38 on land, and 4 on land-fast ice