- Common Name:
- Scientific Name:
- Marmota monax
- Head and body: 17.75 to 24 inches; tail: 7 to 9.75 inches
- 13 pounds
- IUCN Red List Status:
- Least concern
- Current Population Trend:
The groundhog, or woodchuck, is one of 14 species of marmots, a subgroup of the squirrel family. One of the largest members, groundhogs live a feast-or-famine lifestyle: they gorge themselves all summer to build up plentiful reserves of fat, then retreat to their underground burrows to snooze through the winter while drawing their sustenance from body fat. During hibernation, the animal’s heart rate plunges, and its body temperature is not much warmer than the temperature inside its burrow.
Groundhog hibernation gave rise to the popular U.S. custom of Groundhog Day, held on February 2 every year. Tradition dictates that if a groundhog comes out of its burrow and sees its shadow, there will be six more weeks of winter. If not, spring will come early. A comprehensive study from 2021 showed the tradition is a matter of chance—groundhogs make correct predictions only 50 percent of the time.
Groundhogs are widely distributed across North America, ranging as far south as Alabama and as far north as Alaska. They build extensive burrows—anywhere from eight to 66 feet long—with multiple entrances and rooms, including bathrooms. Some groundhogs even have more than one burrow. But these mammals tend to keep to themselves, only seeking one another out when it’s time to mate.
After roughly three months of hibernation, evidence suggests that male groundhogs wake up early to prepare for the mating season. As early as February, they leave their burrows to scope out where females are hibernating. Then they go back to sleep for another month or so until it’s time to mate.
Mating season starts in early March, ideal timing as food becomes more abundant—and there’s just enough time to start packing on the body fat they’ll need for the winter ahead. Females welcome a litter of perhaps a half-dozen newborns, which stay with their mother for several months.
Behavior and diet
Though they are usually seen on the ground, groundhogs can climb trees and are also capable swimmers. These rodents frequent the areas where woodlands meet open spaces, like fields, roads, or streams. Here they eat grasses and plants as well as fruits and tree bark. Groundhogs are the bane of many a gardener as the animals can decimate a plot while voraciously feeding during the summer and fall seasons.
DID YOU KNOW?
— Carnegie Museum of Natural History
Their burrows are also used as homes for other animals including skunks, foxes, weasels, opossums, and rabbits.
— Missouri Department of Conservation
Though their diet mostly consists of vegetation like grasses and fruit, groundhogs can also eat young birds.
— Indiana Department of Natural Resources