Alternate name: Groundhog/Eastern Marmot

Family: Sciuridae, Squirrels view all from this family

Description A large marmot. Grizzled brown (with variations from reddish to blackish); uniformly colored. Prominent bushy tail. Small ears. Short legs. Feet dark brown or black. Incisors white. L 16 1/2–32" (418–820 mm); T 3 7/8–6" (100–152 mm); HF 2 7/8–3 7/8" (75–100 mm); Wt 4 1/2–14 lb (2–6.4 kg).

Similar Species Yellow-bellied Marmot, usually paler and yellower, has whitish spots between eyes and occurs farther south and west.

Breeding 1 litter per year of 4 or 5 young born April–early May, after 28-day gestation. Blind and naked at birth, they open their eyes and crawl at about 1 month and disperse at 2 months.

Habitat Pastures, meadows, old fields, and wooded areas.

Range East-central Alaska and British Columbia south to n Idaho, east through most of s Canada, and south to e Kansas, n Alabama, and Virginia.

Discussion The name Woodchuck comes from a Cree Indian word, wuchak, used to identify several different animals of similar size and color, including other marmots; it denotes nothing about the Woodchuck’s habits or habitat. This sun-loving creature is active by day, especially in early morning and late afternoon. In late summer or early fall, the Woodchuck puts on a heavy layer of fat, which sustains it through hibernation. It digs a winter burrow with a hibernation chamber, where it curls up in a ball on a mat of grasses. The animal’s body temperature falls from almost 97°F (36°C) to less than 40°F (4°C), its breathing slows to once every six minutes, and its heartbeat drops from more than 100 beats per minute to four.

The male emerges in early spring (according to legend, on February 2, Groundhog Day, but much later in northern parts of its range) and seeks out females in its territory. Recent studies of Woodchucks in Pennsylvania have revealed that the pairs meet but don't mate at this time; the male returns to his burrow for another month's sleep, mating with the females he has earlier encountered when he makes his later emergence. These two visits are almost the only time that two adults share a den.

A good swimmer and climber, the Woodchuck will ascend a tree to escape an enemy or obtain a vantage point, but never travels far from its den. Its burrow, up to 5 feet (1.5 m) deep and 30 feet (9 m) long, has one or more tunnels terminating in a chamber containing a large grass nest. Other mammals, including cottontail rabbits, Virginia Opossums, Common Raccoons, skunks, and foxes, may use a vacant Woodchuck burrow, sometimes enlarging it to create a nursery den.

Green vegetation, such as grasses, clover, alfalfa, and plantain, forms the Woodchuck's diet; at times it will feed heavily on corn and can cause extensive damage in a garden.

If alarmed, the Woodchuck often gives a loud, sharp whistle, followed by softer ones as it runs for its burrow, from which it then peeks out. When agitated, it chatters its teeth, and it can hiss, squeal, and growl. The human hunter is the Woodchuck’s major enemy, but the automobile and large predators, especially the Red Fox, also take their toll. While an overpopulation can damage crop fields, gardens, and pastures, Woodchucks are beneficial in moderate numbers. Their defecation inside the burrow, in a special excrement chamber separate from the nesting chamber, fertilizes the earth. Their digging loosens and aerates the soil, letting in moisture and organic matter while bringing up subsoil for transformation into topsoil (in New York State they turn over 1.6 million tons of soil each year).