Five Things You Didn’t Know about Groundhogs

While many Americans would recognize famed Punxsutawney Phil as a groundhog, they may not know much else about the species. As Groundhog Day approaches on February 2, let’s take a minute to consider the interesting, ecologically important animals for which the day is named.

For starters, groundhog is a misnomer, said Chris Whittier, D.V.M., Ph.D., V97, assistant teaching professor of conservation medicine at Cummings School of Veterinary Medicine at Tufts University. They are actually in the same family as chipmunks and prairie dogs.

And even though they may be eating your vegetable garden in the summer, “remember that groundhogs are important native wildlife wherever they exist, said Whittier, who is also director of the school’s master’s program in conservation medicine. “If you happen to have conflicts with them in your yard, there are many resources to help, including these strategies from MassWildlife.”

Here are five takeaways from Whittier as we look forward to Groundhog Day:

1. Groundhogs are also known as woodchucks or “whistle-pigs.” 

The familiar name woodchuck actually has nothing to do with wood, and stems from the Native American names for them: wuchak, wejack, and possibly otchek, which is a name for fishers. The name whistle-pig, which is most common in Appalachia, stems from groundhogs’ habit of making a high-pitched whistling sound, usually as a warning to other groundhogs when they feel threatened. (The pig is similar to how we refer to woodchucks’ rodent-cousin the guinea pig.)

2. They are actually large squirrels. 

Capable of weighing up to 15 pounds, groundhogs are among the largest members of the squirrel family Sciuridae and within the taxonomic tribe of marmots or ground squirrels—a group that also includes chipmunks and prairie dogs. Like these relatives, groundhogs are powerful diggers that make large, complex underground burrows. These burrows are not only potentially helpful to soils for aeration and nutrient recycling, but they are often used by other burrowing animals such as foxes, opossums, raccoons, and skunks.

Whittier's wildlife camera captured this video of groundhogs on Cummings School's Grafton campus.

3. Groundhogs are important intermediaries in the food chain. 

Primarily herbivores, groundhogs eat a variety of plants, including from people’s gardens. But they also may eat things we consider pests, such as grubs, other insects, and snails. They are even reported to eat other small animals such as baby birds. Because of their relatively large adult size and burrowing—not to mention climbing and swimming abilities—groundhogs don’t have many predators aside from coyotes, foxes, domestic dogs, and, of course, humans. (However, baby groundhogs sometimes do fall prey to raptors such as hawks, owls, and eagles.)

4. Pregnancy goes by fast for them. 

Groundhog mating season is in the early spring and, after only a month-long pregnancy, mother groundhogs typically give birth to a litter of two to six blind, hairless babies. Young groundhogs are called kits, pups, or sometimes chucklings. Groundhog families disperse in the fall, and the young reach sexual maturity by two years. Groundhogs typically live three to six years in the wild, but have been reported to live for up to fourteen years in captivity.

5. Groundhogs are among the few species of true hibernators. 

This is the part of their behavior that has led to North American Groundhog Day tradition. After losing up to half their weight while hibernating, groundhogs usually emerge from their winter burrows in February—hence the date of this holiday. The shadow-observing lore has no scientific basis. It was actually imported from a German tradition that bases forecasting on the behavior of the European badger—a totally unrelated small mammal of the carnivore—as opposed to rodent—order, but one that does also burrow and undergo a less intense form of hibernation.