What do they look like?

Woodchucks have a heavy, chunky body with short, powerful legs for digging. Males are slightly larger than females. Woodchucks have an underfur that is thick, woolly and grey with yellow tips. Their outer fur has alternating bands of dark and light colors, making them look frosted. They have small, rounded ears, small black eyes, and a dark, bushy tail. Woodchucks have blackish-brown feet with well-developed claws. They have two teeth that never stop growing. These teeth need to be worn down by chewing or they will continue to grow and hurt, or even kill, the animal. Woodchucks are from 415 to 675 mm long from the head to the tail and their tail is from 100 to 150 mm long.

Where in the world do they live?

Woodchucks (also known as groundhogs or whistle-pigs) are only native to the Nearctic region and are found in parts of Alaska, across southern Canada, and throughout the northeastern and east central United States.

What kind of habitat do they need?

Woodchucks usually live close to woodlands. They prefer fields, roadsides, streams, and agricultural land. They construct burrows and prefer soils that are easy to dig in.

How do they reproduce?

Woodchucks mate in early spring. Females are pregnant for about 30 days. They give birth to from 2 to 7 young that are naked and blind at birth. They are cared for and nursed by their mother in her burrow until they are about 6 weeks old. They are then weaned and leave their mother's burrow soon after that. Woodchucks breed only once per year.

How long do they live?

Woodchucks can live up to six years in the wild, and ten years in captivity.

How do they behave?

Woodchucks are mostly solitary animals, prefering to be alone, although they will sometimes share a den. They are active during the day, but especially in the early morning hours, the late afternoon, and at dusk. When not feeding, woodchucks sunbathe, scratch, and preen themselves outside their den while watching for predators. When in danger woodchucks retreat into nearby dens instead of running. Dens are situated in dry locations. With strong, clawed, forelimbs and large teeth, woodchucks can easily construct burrows with as many as five entrances. These dens are very long, up to 45 ft of tunnels, extending as far underground as 5 ft. Dens in open areas are used in the summer, and those under stumps, at the edge of rock ledges, and near other protection are generally occupied during the winter hibernation. Dens are always kept clean and well padded with vegetation. Occupied dens can be recognized by a pile of fresh earth at the entrance. Woodchucks are true hibernators, relying soley on body fat for winter survival. Hibernation generally begins in October and ends in March or April. Soon after leaving hibernation, sexually mature woodchucks begin the reproductive process. Males tend to venture above ground first and fight vigorously with each other over access to females.

How do they communicate with each other?

Woodchucks are very vocal mammals, hence the name "whistle-pig." When alarmed, a woodchuck gives a loud, shrill whistle. Teeth grinding and chattering are common when woodchucks are cornered. Woodchucks have also been heard to bark, squeal, and whistle when fighting with other woodchucks

What do they eat?

Woodchucks are almost exclusively herbivores and eat a variety of vegetation including dandelion, chickweed, sorrel, clover, alfalfa, beans, peas, grains, and grasses. They sometimes eat insects, snails, and birds' eggs. Woodchucks often sit on their back feet and pull plants over with their forepaws. In early spring, when there is not a lot of green vegetation, they may eat the bark, buds, and twigs of shrubs and fruit trees. They become very fat during the fall in preparation for their winter-long hibernation.

What eats them and how do they avoid being eaten?

Woodchucks use their burrows to escape from predators. They are preyed upon by large predators such as wolves, coyotes, and large hawks and owls. Their young are sometimes taken by snakes.

What roles do they have in the ecosystem?

Woodchucks influence the how many and what kinds of plants there are in their communities by eating them. Woodchucks are also important and abundant food sources for many large predators in their communities.

Do they cause problems?

Woodchucks are agricultural pests. They raid gardens and their burrows damage farm machinery and destroy building foundations.

How do they interact with us?

The burrowing activities of woodchucks often provide homes for many other animals. Also, plant growth around burrows is made better by fertilization from buried fecal materials. The woodchuck is often a subject of entertainment: 1) Outdoor antics of the woodchuck are entertaining to many animal watchers. 2) American folklore of Ground Hog's Day: the supposition is that when the woodchuck arised from hibernation on February 2 and sees its shadow, there will be six more weeks of winter. 3) Many movies have been made with woodchucks (or groundhogs) as the main characters such as both the "Caddyshack" films. 4) "How much wood would a woodchuck chuck if a woodchuck could chuck wood?"

Are they endangered?

As a result of deforestation and maintenance of the land of cultivated fields and pastures, the woodchuck has thrived and multiplied. Woodchucks are favorite targets for sport hunting, which helps control their numbers. Their ability to reproduce quickly is sufficient to prevent local extermination.

Contributors

Jessica E. Light (author), University of Michigan: July, 2001.

References

Baker, R.H. 1983. Michigan Mammals. Michigan State University Press, Michigan, pg. 179-188.

Banfield, A.W.F. 1981. The Mammals of Canada. University of Toronto Press; Toronto, Canada, pg. 107-110.

Jones, J.K. and E.C. Birney. 1988. Handbook of Mammals of the North-Central States.

University of Minnesota Press; Minneapolis, Minnesota, pg. 158-159.

Kurta, A. 1995. Mammals of the Great Lakes Region. Revised Edition. The University of Michigan Press, Ann Arbor, pg. 115-117.

Nowak, R.M. 1991. Walker's Mammmals of the World. Fifth Edition. The John Hopkins University Press, Baltimore, pg. 499-501.