The woodchuck, commonly known as the groundhog, is a large rodent native to North America. This mammal is a member of the ground squirrel family, Sciuridae, and can be found across the eastern and central United States, Canada, and extending into Alaska. The scientific name for this species is Marmota monax. Woodchucks are a familiar sight in fields, pastures, and wooded areas, where they spend their days foraging and maintaining their extensive underground homes.
Defining Characteristics and Kinship
The woodchuck possesses a stocky build and a dense coat of grizzled brownish-gray fur, often with a reddish or yellowish cast. Its body length typically ranges from 16 to 27 inches, with a bushy tail adding four to seven inches. Body weight fluctuates throughout the year, usually falling between four and 14 pounds, with the heaviest individuals recorded just before winter hibernation.
The animal’s physical structure is adapted for its subterranean lifestyle. Woodchucks have short, powerful legs and front feet equipped with four toes bearing long, curved, sharp claws, which are highly effective for digging. Their small, rounded ears and eyes are positioned high on a broad, flat head, allowing the animal to survey its surroundings with minimal exposure when peering out of a burrow entrance.
Burrowing Habits and Winter Sleep
Woodchucks are solitary animals that construct elaborate, multi-chambered burrow systems. These subterranean networks can extend up to 60 feet in length and reach depths of six feet, providing refuge from predators and weather extremes. A typical burrow features a main entrance, often marked by a mound of excavated dirt, alongside several smaller, inconspicuous “plunge holes” used for quick escape.
Inside the burrow, the woodchuck digs specialized chambers, including a nesting area lined with dried plant material for sleeping and raising young, and a separate latrine chamber. They are one of the few true hibernators, entering dormancy typically from October through March or April. During this winter sleep, the animal relies entirely on fat reserves accumulated over the summer and fall.
The physiological changes during hibernation include a drastic drop in body temperature, from a normal of about 99 degrees Fahrenheit to as low as 37 to 42 degrees Fahrenheit. Their heart rate plummets from 80 to 100 beats per minute down to just four or five beats per minute. This deep hibernation allows the woodchuck to conserve energy and survive the months when food is unavailable.
Diet and Reproduction
Woodchucks are primarily herbivorous, feeding on a wide variety of green plants, which they consume in large quantities during the spring and summer. Their preferred diet includes succulent plants like clover, alfalfa, and various grasses, but they also readily eat fruits, berries, and the bark of young trees. They are known to forage on agricultural crops, favoring garden vegetables such as peas, beans, and corn, and they occasionally supplement their diet with small invertebrates like insects.
The mating season begins shortly after the animals emerge from hibernation, typically around February or March. Males often emerge earlier than females. After mating, the gestation period lasts about 31 to 33 days.
The female gives birth to a single annual litter, usually consisting of two to six blind, hairless young, in a prepared nest chamber. The young, called pups or kits, are nursed for approximately six weeks before they begin exploring outside the burrow and eating solid food. By the time they are two to three months old, the young woodchucks become independent and must establish their own burrows.