University of Illinois Extension

Wildlife Directory

Woodchuck or "Ground Hog" (Marmota monax)

Sciuridae
Woodchuck or
The woodchuck (Marmota monax) is the largest ground squirrel found in Illinois. Photo courtesy of Adele Hodde, Illinois Department of Natural Resources.

Did you know?

  • Woodchucks are rodents.
  • Woodchucks are the largest squirrels in Illinois.

Description and Identification

The woodchuck (<i>Marmota monax</i>) is a stocky animal with a short tail. They are much leaner in the spring after emerging from hibernation.
Photo courtesy of Adele Hodde, Illinois Department of Natural Resources.

Woodchucks belong to the family Sciuridae (the squirrel family) and are related to other "marmots" that occur in the western United States. They are a stocky animal with a relatively flat head, blunt muzzle, short legs, and a bushy tail. Their fur is yellowish-gray brown to blackish with the underside often lighter. Woodchucks have small ears and large black eyes. Woodchucks weigh seven to 14 pounds. Males are typically larger than females. Woodchucks are approximately 20 to 25 inches long, including the tail.

Tracks

Woodchuck (<i>Marmota monax</i>) tracks. Notice the track on top has four toes (front paw) and the track on the bottom has five toes (hind paw).
Photo courtesy of Liza Watson.

Woodchuck tracks are fairly easy to identify. They have four toes on the front paws and five toes on the back paws. The tracks will be spaced about four inches apart when walking and twelve inches apart when running. Woodchuck prints are about one and a half inches long.

Droppings

Woodchucks defecate in toilet chambers they dig underground. If you find droppings on your property they are from an animal other than woodchucks.

Habitat

Woodchucks (<i>Marmota monax</i>) prefer to live in open habitats so that they can watch for predators as they graze. 
Photo courtesy of Adele Hodde, Illinois Department of Natural Resources.

Woodchucks occupy a variety of habitats in Illinois but prefer open, well-vegetated areas such as crop fields, meadows, or pastures that are close to a woody edge. They are commonly seen in brushy or weedy areas along fence rows or road right-of-ways. Since they spend much of their time underground, they avoid low-lying areas that flood regularly. The daily home range of a woodchuck varies from 20 to 30 yards to several hundred yards.

Distribution and Abundance

Woodchucks are common throughout the state. They typically live in densities of one or two adults per acre, although in prime habitat there may be more.

Reproduction

Woodchucks do not breed until their second year. Breeding occurs in late February or March. The gestation period is 31 to 32 days, with four to five young born in April or early May. Woodchucks have one litter per year. Young woodchucks will start looking for their own living space when they are approximately two months old.

Food

Woodchuck (<i>Marmota monax</i>) chewing a leaf. 
Photo courtesy of Liza Watson.

Woodchucks feed primarily on plants such as clovers, grasses, ferns, leaves of bushes and trees, and fruit. In early spring, they eat bark and small branches before the new plant growth emerges. If they have access to garden and field crops they will eat beans, peas, carrot tops, alfalfa and soybeans. They also occasionally eat snails, insects, eggs and young birds. They are also known to climb trees to reach buds and leaves. An adult woodchuck can consume one to one and a half pounds of vegetation per day.

Behavior

Woodchuck (<i>Marmota monax</i>) at a burrow entrance. 
Photo courtesy of Liza Watson.

Woodchucks are diurnal (most active during the day), particularly in the early morning and late afternoon hours. They stay close to their burrows when feeding and typically only stay above ground a couple of hours per day.

Unlike most mammals in Illinois, woodchucks are true hibernators. They begin hibernation in October or November and come out of hibernation in mid- to late February. Researchers have found that while in hibernation a woodchuck's body temperature drops from about 97°F to 34°F, its breathing slows to approximately one breath every six minutes, and its heart beats only four times per minute.

Woodchucks live primarily underground in burrows dug on land with a slight slope. They excavate winter and summer burrows. Winter burrows are often dug in wooded areas and have only one opening. The hibernation nest is located at the end of the burrow, lined with grass, and blocked off with soil during hibernation. In the spring, the woodchucks emerge from hibernation and move to grassy areas or agricultural fields where they dig a summer burrow. The summer burrow has two or more entrances. The main entrance is typically ten to twelve inches wide and will have a mound of soil next to it. Other entrances are dug from below the soil surface and lack the mound of soil. These entrances provide the woodchuck with quick access to the burrow to escape from predators. Often more than one summer burrow is excavated. Each burrow system can be quite extensive, with a main nest chamber, a toilet chamber located away from the main nest, and additional chambers found throughout the burrow.

Except during the breeding season, when a male and female will share a burrow, woodchucks are typically solitary animals. They are territorial and will defend their burrow against intruders. When threatened they chatter their incisors and use short, sharp whistles to warn other woodchucks of danger. Woodchucks are not fast runners, but are capable of defending themselves when threatened.

Longevity

The average life span of a woodchuck is three years. Coyotes, foxes, bobcats, weasels, dogs, owls, and hawks prey upon woodchucks. Woodchucks are often killed by vehicles, because they move relatively slowly.

Damage Prevention and Control Measures

Woodchucks may damage garden vegetables, field crops, or orchard and nursery stock. The entrances to their burrows can be hazardous to people or livestock if they step into them. Woodchucks often cause only minor damage to properties. However, if there are many woodchucks on a single property, or one animal is being overly destructive, there are several ways that landowners might remedy the situation.

Habitat Modification

Given their habitat requirements, it is difficult to modify a property to discourage woodchucks. Properties with some slope to the land will be more likely to attract woodchucks than those that are relatively flat.

Exclusion

If there is a small area of property that you want to protect from woodchucks, such as a garden or a group of fruit trees or ornamental shrubs, fencing can help reduce the damage. Woodchucks are skilled at climbing and digging. Therefore, to keep a woodchuck out, fences must be at least three feet high. The top of the fence should make a 45° angle to prevent the woodchuck from climbing over the fence. Since they burrow, a wire deterrent (heavy poultry wire, welded wire) below the fence line must be used to keep them from digging under the fence. Bury the wire 12 to 14 inches underground, bending the lower edge (bottom two to four inches) of the wire at a 90° angle pointing out from the fence line. An electric hot-shot wire located four to five inches above the ground outside the fence will discourage climbing and burrowing. Use hardware wire to exclude woodchucks from digging under porches and decks.

Repellents

Currently there are no approved repellents or toxicants for woodchuck control in Illinois.

Fumigants

Carbon monoxide gas cartridges can effectively kill woodchucks. You will need an animal removal permit from the Illinois Department of Natural Resources before using fumigants to control woodchucks.

Because gas cartridges pose potential fire and gas accumulation hazards, they should never be used near homes or other buildings. For best results, burrows should be treated on cool, rainy days or during periods of woodchuck inactivity to make sure the woodchuck is in the burrow and not out foraging for food. Vacant burrows may be reoccupied by woodchucks from nearby areas so all fumigated burrows should be rechecked weekly for a month. Other species may also take over the burrow, so keep an eye out for signs (tracks, scat, food remains) that show a fox, coyote, or other animal has moved into the burrow.

Removal
Photo courtesy of Liza Watson.

Removal of a woodchuck is only necessary if the animal is causing substantial property damage or is a public health or safety concern. Since it is difficult to modify habitat to discourage woodchucks, be prepared to have other woodchucks take up residence on your property if you remove the animal that is causing damage. Exclusion is a better method to control woodchucks than removal.

To remove a woodchuck from your private property, you will need an animal removal permit from an Illinois Department of Natural Resources District Wildlife Biologist. Woodchucks can be Iive trapped using a welded wire or metal live trap baited with apples. Traps should be checked at least once a day. Woodchucks must be released or euthanized within 24 hours of capture. If the animal will not be released on the same property where it was trapped, you will need written permission from the landowner to release the woodchuck on another property. As with all other mammals, it is not permitted to release woodchucks in public parks, forest preserves, or natural areas.

If you prefer to have someone else trap and remove the woodchuck for a fee contact a nuisance wildlife control operator.

Public Health Concerns

Woodchucks can be carriers of tularemia, but they are not considered a public health risk. Tularemia is caused by the bacterium Francisella tularensis. Symptoms can include fever, chills, headache, diarrhea, joint or muscle pain, and weakness. People can contract the disease from handling infected carcasses.

Ecological Role

Notice the large amount of soil surrounding the woodchuck burrow entrance. 
Photo courtesy of Laura Kammin, University of Illinois Extension.

Abandoned woodchuck burrows provide shelter for a number of wildlife species including rabbits, raccoons, foxes, skunks, weasels, and opossums. Additionally, woodchucks move large amounts of subsoil when digging their burrows, which helps to aerate and mix the soil.

Legal Status

In Illinois, woodchucks are protected as a Game animal. Woodchucks in urban areas that cause problems may be removed if an animal removal permit is issued by an Illinois Department of Natural Resources District Wildlife Biologist.

In rural areas, a hunting or trapping license from the IDNR is required to hunt or trap woodchucks. Woodchucks may be hunted during most of the year, except during April and May and during firearm deer hunting season. Woodchucks may be trapped from June through September. There is no limit on the number of woodchucks that may be taken by a licensed hunter or trapper. For full hunting and trapping regulations, visit the IDNR Licenses & Hunting website.