Many bears that live in cold regions of the world sleep more than a lot – they spend the entire winter in a deep sleep. This is known as the bear's winter dormancy. The bear does not go into true hibernation, as its pulse rate does not drop and its body temperature only falls by a few degrees. It seems to sleep as a way of coping with a shortage of food in the depths of winter; if it is less active it is using far less energy and so can live on its fat stores until food is available again.
In preparation for its period of sleep, a bear will eat a phenomenal amount of food the preceding autumn. And, if food is readily available, the bears manage to keep their eyes open and opt to stay awake and eat normally. The decision is dependent on the food supply, it is not an inbuilt mechanism in response just to cold weather.
In preparation for its period of sleep, a bear will eat a phenomenal amount of food the preceding autumn. And, if food is readily available, the bears manage to keep their eyes open and opt to stay awake and eat normally. The decision is dependent on the food supply, it is not an inbuilt mechanism in response just to cold weather.