Why do bears hibernate during the winter months?
Winter brings on many changes in animals lives, whether it be migration by animals such as the whales, seals, turtles, eels, crabs, fish, butterflies etc. However, for some animals hibernation is the preferred method of escaping the cold of winter. For example, the small ground squirrel illustrates some of the remarkable changes that take place. It’s body temperature drops to within a few degrees of the cold outside its den. The heart will beat only once or twice a minute. When it is active, the squirrel may breathe a few hundred times each minute, but in hibernation it takes a slow breath only once every five minutes. Despite these changes, its blood remains saturated with oxygen, and little used muscles remain in tone ready for action when they awaken. Bears however, are not true hibernators. The body temperature of bears stays normal. They burn an estimated 4,000 food calories a day. While in hibernation they can awake and move about quite often. Yet they can exist for three months
