Generally solitary or in female-offspring groups; aggregations of adult males occur during ice-free period along western Hudson Bay. Sometimes wanders long distances but usually stays in one general area from one year to the next (Reeves et al. 1992). Few predators except man, sometimes killer whale. Unlike other bears, only pregnant females winter in dens; denning is seen as a reproductive strategy (providing a protective environment for young) as opposed to a foraging strategy as it is with other bears, since seal prey is available year-round (Amstrup 2003).