Scientific Name: Marmota monax

Habitat: Woodchucks live in open forests, forest edges, and rocky areas and by roadsides.

Reproduction: The young are born four weeks after mating. Although blind, hairless, and very small at birth, they are ready to leave and play outside a month after birth.

Physical description: Woodchucks have heavy bodies with short legs, the body being the thickest part on the animal.  The body is between 18 and 27 inches long with a tail extending another 6 inches.  They weigh between 10 and 14 pounds.  Some may weigh up to 20 pounds!

One of the most obvious characteristics of woodchucks is the two front teeth that stick out of the mouth.  These teeth are for gnawing and they will continuously grow throughout the woodchuck’s life because they are constantly being worn down.

            Woodchucks have two layers of hair, the outer coat is made of course hair with a reddish-brown, gray, or white coloring.  The inner layer is a soft hair of  pale color and is used as insulation by the animal during hibernation.    The legs and tail have a dark brown or black coloration to them, and the hair is very short.  The belly is thinly lined with coarse hair but has no inner layer of insulation.

            Shedding of fur is done annually and has been observed to happen in April, May, and June.  The molting process begins at the tail and head at the same time.  The molt progresses down from the head and up from the tail until it meets in the middle where it is completed.  During this process hair seems blotchy because the new hair is brighter.  Albinism and melanism does occur in woodchucks.  Albinism occurs from a recessive gene received by one of the parents, who can be of normal coloration.  Melanism is from an abundance of dark pigment in the skin and hair.

Calls/Displays: When a woodchuck hears or sees a predator, they will make a shrill whistle to warn others of the pending danger.

Taxonomic affiliation: The scientific name genus and species, of woodchucks is Marmota monax.  They belong to the Order Rodentia and Family Sciuridae.  Like all rodents, woodchucks have no canine teeth or “fangs” and are bucktoothed.  This classifies them as gnawing mammals, a main characteristic of the Order Rodentia.

General Biology, Reproduction, and Behavior: Woodchucks are primarily active during daylight hours. When not feeding, they sometimes bask in the sun during the warmest periods of the day. They have been observed dozing on fence posts, stone walls, large rocks, and fallen logs close to the burrow entrance. Woodchucks are good climbers and sometimes are seen in lower tree branches. Woodchucks are among the few mammals that enter into true hibernation. Hibernation generally starts in late fall, near the end of October or early November, but varies with latitude. It continues until late February and March. In northern latitudes, torpor can start earlier and end later. Males usually come out of hibernation before females and subadults. Males may travel long distances, and occasionally at night, in search of a mate. Woodchucks breed in March and April. A single litter of 2 to 6 (usually 4) young is produced each season after a gestation period of about 32 days. The young are born blind and hairless. They are weaned by late June or early July, and soon after strike out on their own. They frequently occupy abandoned dens or burrows. The numerous new burrows that appear during late summer are generally dug Fig. 3. Burrow system of the woodchuck. Side entrance Nest chamber Main entrance Fig. 2. Range of the woodchuck in North America. B-185 by older woodchucks. The life span of a woodchuck is about 3 to 6 years. Woodchucks usually range only 50 to 150 feet (15 to 30 m) from their den during the daytime. This distance may vary, however, during the mating season or based on the availability of food. Woodchucks maintain sanitary den sites and burrow systems, replacing nest materials frequently. A burrow and den system is often used for several seasons. The tunnel system is irregular and may be extensive in size. Burrows may be as deep as 5 feet (1.5 m) and range from 8 to 66 feet (2.4 to 19.8 m) in total length (Fig. 3). Old burrows not in use by woodchucks provide cover for rabbits, weasels, and other wildlife. When startled, a woodchuck may emit a shrill whistle or alarm, preceded by a low, abrupt “phew.” This is followed by a low, rapid warble that sounds like “tchuck, tchuck.” The call is usually made when the animal is startled at the entrance of the burrow. The primary predators of woodchucks include hawks, owls, foxes, coyotes, bobcats, weasels, dogs, and humans. Many woodchucks are killed on roads by automobiles.

Range:  Woodchucks can be found in Alaska, east into Canada and into the eastern half of the United States.  They can be found as far south as northern Georgia and Alabama.