For Some Animals, Autumn Means a Feeding Frenzy Before the Big Sleep

Grizzly Bear Feeding on Salmon

From the latter stages of summer into late fall large animals, such as the grizzly bear, enter a metabolic phase known as hyperphagia; that is, they begin to eat enormous amounts of food to store as fat in order to carry them through the winter. During these winter months some animals will enter a state of deep sleep known as hibernation. The function of hibernation for most animals is to conserve energy long enough to survive the adverse weather conditions and extremely low temperatures of winter when food supplies are at their lowest.

Hibernation habits vary with different animals. Hibernating Ground SquirrelWhile in hibernation some animals will achieve a deep sleep, slowing the heart rate and breathing, and lowering its body temperature and metabolism to a minimum while the body uses its body fat reserves. With this type hibernation, a much deeper sleep is achieved, as opposed to regular sleep, where the animal does not move at all — even when touched — and can take a considerably long time to wake up. Some bears may sleep through the whole winter while other bears may wake for a mid-winter’s walk. Smaller animals, like the chipmunk, cache food such as nuts and seeds, occasionally waking long enough to eat from the cache. Still other animals, like amphibians and reptiles, don’t actually hibernate but rather enterĀ  dormant states called brumation or torpor.

Learn more about hibernation and other over-wintering animal behavior such as migration that animals use to cope with seasonal changes through eLibrary’s Research Topics. You can also browse the Animal Behavior Topic area, which includes a section on hibernation. Here are a few articles to get you started.

The Secrets of Winter Sleep

Lessons From the Torpid

Cold-Blooded in the Cold: Hibernation

Facing the Winter

The Lemur Underground

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