Subscribe Now! National Geographic Magazine $15
Visit our Online Shops

Sign up for free

Newsletters

Once a month
get new photos
and expert tips.

Groundhog
Marmota monax

Photo: A groundhog sitting in the grass
A groundhog sitting in the grass
Photograph by Melissa Farlow

Groundhog Profile

The groundhog, or woodchuck, is one of 14 species of marmots. These rodents live a feast-or-famine lifestyle and gorge themselves all summer to build up plentiful reserves of fat. After the first frost, they retreat to their underground burrows and snooze until spring, drawing their sustenance from body fat. While hibernating, 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 American custom of Groundhog Day, held on the second of February every year. Tradition dictates that if a groundhog sees its shadow that day, there will be six more weeks of winter, though such a prediction seems a sure bet over much of the groundhog's North American range.

In the spring, females welcome a litter of perhaps a half dozen newborns, which stay with their mother for several months.

Groundhogs are the largest members of the squirrel family. Though they are usually seen on the ground, they 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. They can decimate a plot while voraciously feeding during the summer and fall seasons.

Fast Facts

Type: Mammal
Diet: Herbivore
Size: Head and body, 17.75 to 24 in (45 to 61 cm); Tail, 7 to 9.75 in (18 to 25 cm)
Weight: 13 lbs (6 kg)
Size relative to a 6-ft (2-m) man:
Illustration of the animal's relative size

Multimedia

Small Mammal Features

Photo: American bison

Historic Journey

Follow in Lewis and Clark's footsteps in this cross-country interactive journey.

Photo: Hedgehog

Kids: Hedgehog Creature Feature

Get fun facts on hedgehogs, plus video, audio, photos, and more at National Geographic's Kids site.

Photo: Meerkats

Stand Tall

Tunnel into the strange social life of the meerkat, Africa's most beloved carnivore, in this multimedia feature.

Other Small Mammals

Map: Locator map for the groundhog
 Groundhog range

Special Advertising Sections

Photo: Puffin

Photo Contest

Think your photo is the "Ultimate" winner? Submit your best in six different categories.

Photo Gallery

See how Lipton is dedicated to sustainable agriculture. View pictures from Boyd Matson's trip to Africa.

Mammals Right Rail

Get the Latest Headlines

Photo: Grizzly bears

Make us your online news source.

Get Animal Pictures

Photo: Lion yawning

Get your daily dose of photos.

Get the Call of the Wild

Image: Mobile phone and lion

Make your phone roar like a lion or howl like a coyote with Nat Geo Mobile.

For Kids!

Photo: A cartoon dog

It's no stretch to find fun facts on our Kids site!

Shop National Geographic DVDs

Whatever your interest, you'll be entertained and educated with our collection of best-selling DVDs.