Why do bears hibernate? It is a method to conserve energy when weather conditions are bad and food is scarce. (Bears that live in warm climates often don't hibernate at all!)
During the months before hibernation, bears eat up to 20,000 calories a day and can put on up to 30 pounds of body fat to get them through the winter!
Black bears enter their dens in November.
Hibernation in black bears typically lasts 3–5 months.
During this time, their heart rate drops from 40–50 beats per minute to 8 beats per minute.
A special hormone, leptin is released into their systems, to suppress appetite.
Because they do not urinate or defecate in the den, the nitrogen waste from the bear's body is recycled back into their proteins. (This also prevents muscle loss, as the process uses the waste products to build muscle during the long periods of inactivity.)
Their body temperature, however, does not drop significantly and they remain somewhat alert and active. (If the winter is mild enough, they may wake up and forage for food.)
Females give birth in February and nurture their cubs until the snow melts.
The footpads peel off while they sleep, making room for new tissue.
After emerging from their winter dens in spring, they wander their territories for two weeks so that their metabolism accustoms itself to the activity.
**So everyone practice being a bear this winter and make sure to get a couple good naps in!
