Wild Facts: Winter’s deep sleep

Published 2:34 pm Thursday, December 4, 2008

Submitted by the Georgia Department of Natural Resources



Some mammals hibernate to survive winter. Shorter day lengths, falling temperatures and a decrease in available food trigger this gradual state of inactivity. To conserve energy and fat reserves, a hibernating animal’s heart rate slows down, its body temperature lowers (sometimes close to freezing) and its metabolism decreases.

Depending on the species and the weather, hibernation may last several days or weeks. Examples of hibernating wildlife include bats, groundhogs and some mice. Although bears retreat to their dens in winter, they are not considered true hibernators. Bears are easily awakened, unlike the small mammals that go through significant physiological changes and fall into a deep sleep.



Wild Facts is a regular feature written by Linda May, a wildlife interpretive specialist with the Georgia DNR Wildlife Resources Division.