Bear
Behavior and life history
Bears of northern regions, including the American black bear and the grizzly bear, hibernate in the winter. During hibernation, the bear's metabolism slows down, its body temperature decreases slightly, and its heart rate slows from a normal value of 55 to just 9 beats per minute. Bears normally do not wake during their hibernation, and can go the entire period without eating, drinking, urinating, or defecating. A fecal plug is formed in the colon, and is expelled when the bear wakes in the spring. If they have stored enough body fat, their muscles remain in good condition, and their protein maintenance requirements are met from recycling waste urea. Female bears give birth during the hibernation period, and are roused when doing so.
Bear-39