Hibernation

Hibernation is a state of dormancy and inactivity used by bears to adapt to limited winter food supplies.

Hibernation of bears is different from other hibernating animals, such as bats, marmots, squirrels, woodchucks and rodents that are in a deep sleep, with a low metabolic rate and temperatures many degrees below normal. Several weeks are required to reach that state of dormancy.

During a bear's hibernation, its body temperature does not drop to within a few degrees of the surrounding air. Its metabolic rate is comparatively high, and it may awaken during a warm period and move about near the den.

The specific lengths of hibernation depend on climate, location, gender, age group and reproductive status of the individual bear. Some bears do not hibernate in areas where food is readily available and where there is warmer climate. Bears in poor physical condition, with an inadequate fat reserve, may hibernate for a short period of time, or not hibernate at all.