Animals That Hibernate In Winter

Fat-Tailed Dwarf Lemur The fat-tailed dwarf lemur is the only primate known to engage in a combined hibernation and torpor state for an extended period of time. Endemic to Madagascar, the nocturnal lemur hibernates during the dry season when water is scarce."Fat-Tailed Dwarf Lemur". During this hibernation, fat-tailed dwarf lemurs also engage in periods of warming and increased heart rate.

Box Turtles Like hibernation, brumation is a period of inactivity during winter. Unlike hibernation, however, brumation does not involve sleep. It varies from one turtle species to another, but box turtles generally dig a nice hole and brumate during winter for a few months.

Groundhogs Traditionally relied upon to predict the weather, groundhogs (or woodchucks as they are also known) are true hibernators. The hibernation period can last up to five months, and during that time, a groundhog will lose as much as a fourth of its body weight.

Common Poorwill The common poorwill has the distinction of being the first documented hibernating bird. Reduced food supply and harsh temperatures cause the common poorwill to hibernate. While other birds migrate or enter brief states of torpor like the hummingbird, the poorwill can be in a torpid state for several months.

Hedgehogs Toward the end of autumn, hedgehogs enter a state of torpor. In preparation, they look for the best places to build their nests, usually in a big pile of leaves or underneath old buildings or sheds. Hedgehogs tend to awaken during hibernation, as often as every two to four days, or as infrequently as once per month.

Wood Frogs If it's late winter or early spring and you find a frog that’s not moving, it might be a hibernating wood frog. During hibernation, the wood frog’s heart actually stops beating and 35 to 45 percent of its body becomes frozen.

Snails Not all snails hibernate, but when they do, it's an interesting process. Snails hibernate any time the weather is extreme: in hot weather, when the process is known as estivation, and in cold temperatures. 

Skunks Skunks are not true hibernators, but like hedgehogs, they may enter a state of torpor. For those in northern areas, skunks have longer periods of torpor, lasting a few months; in more southern regions, the period of dormancy is much shorter. 

Snakes Nearly all snakes will experience some form of brumation (hibernation for cold-blooded animals), though the length of dormancy depends on location. For instance, a snake in Minnesota might hibernate for months, while one in southern Texas might only go a few weeks.

Bats Bats go into a state of torpor when temperatures get cold and they need to conserve energy. Torpor in bats can last from a couple of hours to a month. During this time, the bat's heartbeat can go from 200 to 300 beats per minute down to as few as 10.