Polar bear the fourhorn sculpin. With the exception of pregnant females, polar bears are active year-round, although they have a vestigial hibernation induction trigger in their blood. Unlike brown and black bears, polar bears are capable of fasting for up to several months during late summer and early fall, when they cannot hunt for seals because the sea is unfrozen. When sea ice is unavailable during summer and early autumn, some populations live off fat reserves for months at a time, as polar bears do not 'hibernate' any time of the year. Being both curious animals and scavengers, polar bears investigate and
Polar bear cannot defend it from larger polar bears. After feeding, polar bears wash themselves with water or snow. Although polar bears are extraordinarily powerful, its primary prey species, the ringed seal, is much smaller than itself, and many of the seals hunted are pups rather than adults. Ringed seals are born weighing and grown to an estimated average weight of only . They also in places prey heavily upon the harp seal ("Pusa groenlandica") or the harbor seal. The bearded seal, on the other hand, can be nearly the same size as the bear itself, averaging . Adult male bearded seals,