Woodchuck Osborn


Marmota monax
Chuck Fergus
Known by many names — chuck, groundhog, whistle pig, marmot, monax and others, the woodchuck is a common Pennsylvania game animal. Members of the order Rodentia (rodents) and family Sciuridae (squirrels), woodchucks are closely related to tree and ground squirrels, chipmunks, prairie dogs and marmots. Chucks dig burrows; these holes aerate the soil and provide excellent escape hatches for many other animals, but they are dangerous to livestock and farm machinery. So the woodchuck is often thought of as a “valuable nuisance”  a contradiction in terms that illustrates well this inhabitant of field and fencerow.

Woodchucks are 20 to 26 inches long, including a bristly, 6-inch tail. Weights of adult chucks vary from 5 to 10 pounds, with extremely large animals as heavy as 12 to 15 pounds. The weight of an individual fluctuates in a cyclic fashion throughout the year, with the animal at its heaviest by summer’s end.

Woodchucks have yellowish-brown to blackish-brown fur. Belly fur is sparse and usually paler than the fur on the back. The pelt is coarse and has little or no commercial value. Light-colored hairs in the coat give some individuals a grizzled appearance. Albinism and melanism occur infrequently. A chuck’s feet are dark brown or black, and its front incisor teeth are white. These two front teeth are broad and chisel-shaped like those of rabbits and squirrels and are used primarily to nip off vegetation. They identify the woodchuck as a rodent.

Woodchucks are found throughout Pennsylvania in open fields, meadows, pastures, fencerows and woodland edges and even deep in the woods. Adults rarely move more than a half mile within their home ranges, preferring to stick close to the safety of the burrow.

Chucks don’t generally have to move far to find food, as they eat a wide variety of vegetation  including green grasses, weed shoots, clover, alfalfa, corn in the milk stage, dandelion greens, garden vegetables such as beans, peas and carrots and, in the fall, apples and pears. These feeding habits often get them in trouble with farmers and gardeners. In the summer, woodchucks feed most actively during early morning and late evening. 

A woodchuck has keen senses of sight, hearing and smell. Note where the animal’s sensory organs are located on its skull: eyes, ears and nose are all near the top of the head, enabling a groundhog to check its surroundings simply by sticking its crown out of the burrow. When feeding, a chuck usually raises its head every 10 seconds or so to check for danger.


Pennsylvania Game Commission
Bureau of Wildlife Management
Attn: Mammal Atlas Coordinator
2001 Elmerton Avenue
Harrisburg, PA 17110
Pennsylvania Game Commission
Bureau of Wildlife Management