Groundhog, Marmota monax, mom and pups

A Quiz To Test Your Knowledge On Groundhogs

Groundhog, Marmota monax, mom and pups

  February 2nd, It's Groundhog Day!

February 2nd is the day each year in which we look towards a giant rodent to find out how much more winter we'll have to endure. This year, we probably know the answer: winter hasn't been very wintry.

According to tradition, the groundhog, Marmota monax, also known as a woodchuck or whistle pig, peeks out of its burrow on February 2nd and checks to see if it has a shadow. If sunny enough for a shadow, the groundhog will return to the comfort of its burrow, and winter will continue for an additional 6 weeks.

The name woodchuck has nothing to do with wood or chucking. The name is derived from the Algonquian name for the critters, wuchak.

Groundhog or Woodchuck
Marmota monax
Lifespan 3 years
Weight 13 pounds
Length 25 inches
Color Various shades of brown
Sexual Maturity 3 years
Gestation Period 32 days
Litter Size 4-6 chucklings
Adult Predators Coyotes, Foxes, Dogs


This stout-bodied rodent weighs up to 13 pounds and has a body length of up to about 20 inches and a short, bushy tail up to 7 inches long. Thick fur on the upper parts ranges in color through various shades of brown. The feet are darker, and the underparts are buff. Melanistic (nearly black) and albino individuals sometimes occur in some populations.

Found from the eastern and central United States northward across Canada and into Alaska, they most commonly live along forest edges abutting meadows, open fields, roads, and streams, but they are occasionally also encountered in dense forests. The groundhog is solitary except in the spring.

Groundhog teeth

Groundhogs have four incisors, shaped like chisels, two upper and two lower of which the upper two continue to grow at the rate of 1/16 of an inch every week! To keep the growth of the front teeth in check the groundhogs have to constantly chew or gnaw on leaves or grass. They also spend a good amount of time nibbling at trees or roots so that the teeth can be worn down. The groundhog defends itself from predators by using its two large incisors and claws.

  Look Up!

Though they spend most of their time on or under the ground, groundhogs can also climb trees.


Groundhog emerging from its burrow

Both male and female groundhogs tend to occupy the same territories year after year. For females, there is very little overlap between home ranges except for the late spring and early summer, as females try to expand their territories. During this time, their ranges may overlap by as much as 10 percent. Males have non-overlapping territories as well, though any male territory coincides with 1 to 3 mature females' territories.

Interactions between female groups — even when those groups are shared by the same adult male — are rare and aggressive. Even though daddy groundhog doesn't live at home, from the breeding season through the first month of the infants' lives, he visits each of his female groups every day.

Groundhogs are active during the day. In summer they commonly feed in the early morning and the late afternoon, spending the rest of the day sleeping or basking in the sun. In late summer they begin to put on weight in preparation for the move to their winter dens, often located in wooded areas. They hibernate from October through March. While hibernating, a groundhog's body temperature drops from 99°F to 40°F, and its heartbeat drops from 100 beats per minute to 4 beats per minute!

Groundhogs can swim in order to evade predators or survey their territory for potential food sources. Their net legs make it easy to swim, and the paddles allow you to sail the water. Its tail is mighty and can also be used as a defensive device – either by hitting an enemy or slamming it into the water to create an intense splash. Groundhogs can swim at about 2 miles per hour.

  Groundhog Burrows

Groundhog burrow graphic

Groundhogs live in extensive burrows two- to six-feet deep and up to 40 feet long that contain numerous chambers with specific functions, such as for nesting or for wastes. You can usually spot the main entrance by an adjacent large mound of dirt, which these animals use for observation and sun-basking. In addition, there may be as many as five other openings to the den.

  Food and Diet

Mainly vegetarians, groundhogs feed on a variety of grasses and chickweeds, clover, plantains, and many varieties of wild and cultivated flowers. They eat blackberries, raspberries, cherries, and other fruits, along with the bark of hickory and maple trees. Of course, to the chagrin of gardeners, groundhogs love fresh produce, as well. They will even eat grasshoppers, June bugs, and other large insects.

  Groundhog Reproduction

Groundhog footpring

Woodchucks do not mate until their second year. The average life span for a woodchuck in the wild is five to six years. Males and females breed in March or April, after which they have no further contact. The female groundhog raises the chucklings alone.

Woodchucks give birth from early April to mid-May following a 32-day gestation period. One litter contains four to six kits. The young open their eyes at four weeks and are weaned at 6 weeks, when they’re ready to leave the burrow with their mother. In the fall the young woodchucks venture off to seek their own territories.

Infants stick around home for only about 2 to 3 months after being born and then they disperse and leave mom's burrow. However, a significant proportion, about 35% of females stick around longer, leaving home just after their first birthdays, right before mom's new litter arrives.

  Groundhog Prevention and Control

What do groundhogs eat? Groundhogs eat everything from flowers to vegetables. Favorite foods include alfalfa, clover, peas, beans, lettuce, broccoli, plantain, and soybeans. Groundhogs will often devour your seedlings before they even have time to grow. If you don’t have vegetables around, groundhogs will settle for twigs, bark, bugs, and blossoms.

These critters may have been attracted by your garden full of tasty plants. Encourage them to go elsewhere.

Groundhog in a Have-A-Heart trap

  Sprinkle blood meal, ground black pepper, dried blood, or talcum powder around the perimeter of your garden. You can try using hair clippings as well.
  Puree and strain hot peppers and garlic, mix them with water and enough liquid soap to make it stick, and spray it liberally around the garden.
  Put some harmless but strong-smelling substance just inside the burrow (such as urine-saturated clumps of kitty litter). Loosely seal the entrance, so the smell stays inside the burrow.
  Would you eat lettuce tossed with bobcat urine? Neither would a woodchuck! Fox, coyote, wolf, and bobcat urines are among the forbidding predator scents now sold as groundhog repellents.
  Keep undergrowth and grass cover low to deter groundhogs.
  Groundhogs are always looking for vacant burrows. Close down their tunnel systems. Bury 3-foot square panel of welded wire, centered over the entrance hole before an abandoned burrow is rediscovered.

  Do Groundhogs Make Good Pets?

Groundhogs do not make good pets, as they obviously dig and chew through almost anything in their path. Odds are, they will find a way out of a cage and will escape eventually. It is especially important that you do not try to keep baby groundhogs, even if you know they are orphaned. It is best to call your local animal control or an animal shelter to ask if they can take them in and rehabilitate them. Baby groundhogs are very sensitive, and can die if not given the proper attention. Despite being cute, groundhogs do not make good pets.

Further Reading:

 Beavers — Nature's Hydrologist, Part 1
 Wisconsin's Rabbits and Hares
 Garter Snakes — The Gardener's Friend
 Wisconsin Native Salamanders
 Voles, Both The Good and The Bad

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