The woodchuck (Marmota monax), belongs to the marmot family, and goes by many names, including groundhog and whistle pig due to the sound they make through their large teeth to warn one another of danger.
While there are several species of marmots in North America, our woodchuck is found mostly in the eastern United States and across much of southern Canada. In New England, woodchucks inhabit both urban and suburban yards, fields, meadows, woodland clearings, and we see them frequently in grassy areas along highways.
Woodchucks have short, muscular legs designed for digging, and large front incisors that they must wear down by chewing to curb tooth growth. They often grow up to 20 inches in length, with a tail that measures roughly six inches long, and generally weigh between six and 12 pounds.
Woodchucks 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.
Woodchucks are among the few true hibernators found in Massachusetts. 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 woodchuck’s body temperature drops from 99°F to 40°F, and its heartbeat drops from 100 beats per minute to 4 beats per minute!
They don’t have too many predators because of their size, though foxes, raccoons, hawks, and dogs will go after young.
Food & Diet
Mainly vegetarians, woodchucks 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, woodchucks love fresh produce, as well. They will even eat grasshoppers, June bugs, and other large insects.
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 raises the young 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 six 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.
Woodchucks 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.
Situations & Solutions
To the dismay of gardeners, woodchucks love fresh vegetables, especially broccoli, peas, beans, carrot tops, lettuce, and squash. Common flower garden targets include asters, daisies, lilies, marigolds, pansies, phlox, snapdragons and sunflowers. Some homeowners find the burrowing holes woodchucks dig in the lawn a nuisance. Additionally, woodchucks often conceal their entrance hole by placing it under a building.
Fortunately, there are several non-lethal ways to deter these animals.
Woodchucks in the Garden
Fencing offers the only viable way to protect plants from woodchucks. Ideally, you want to install fencing before the woodchuck gets a taste of any produce, as this will lessen the animal’s determination to get through the barrier.
Because woodchucks can burrow under and climb over fencing, you’ll need to install your fence with one of the following methods:
Purchase chicken wire that’s at least 6 feet high. As you install the wire around the perimeter (with the help of 5-foot posts), be sure to bury the wire at least 10 inches in the ground. At the top of the wire, leave 12 inches unattached from your posts, and bend the fencing outwards, so that the woodchuck can’t get a good grip to climb over it.
You can also place 3-foot-wide chicken wire flat on the ground around the perimeter of the garden. After you’ve installed this ground wire, secure a 4- to 6-foot high vertical fence that’s 6 inches from the edge closest to the garden (see figure).
As shown in the diagram (click image for larger version), there will be 2½ feet of chicken wire on the outside of the vertical fence and 6 inches on the side closest to the garden. Leave the top 12 inches of the vertical fence unsecured and bent outward, away from garden.
The woodchuck won’t be able to dig under the vertical fence because of the chicken wire underneath.
Options Beyond Fencing
If proper fencing isn’t possible, you have a few more options, but these are by no means guaranteed.
- You can try planting species that repel woodchucks, such as gopher plant (Euphorbia lathyrus) or crown imperial fritillary (F. imperialis) around the garden.
- Repeated treatments of planted areas with various repellents, such as fox or coyote urine, diluted Tabasco sauce or red pepper flakes, or scattered human hair are other reported deterrents.
- Allowing a pet dog access to the planted area may also help deter woodchuck visits.
- Constructing a visibility barrier, such as a three-foot black plastic wall, before any woodchucks identify the area as a foraging ground, may also prove effective.
Woodchuck Hole Hazards
Don’t interfere with woodchuck burrows until after the young are capable of leaving (approximately July 1.) If woodchuck holes in walkways present a potential hazard to people, pets or farm animals, flag them with something visible (traffic cone, a red flag) to alert others.
Once the young are able to leave, locate all the holes and stuff all but one with rags soaked in olive oil. As the olive oil becomes rancid, it will give off an odor repugnant to the woodchucks and they will relocate. Of course, there’s no guarantee that they will leave the property; they may just move to another location in the same yard.
Woodchucks Under Buildings
Woodchucks often conceal their entrance hole by placing it under a rock, in a thicket, or, in many cases, under a building. Rarely do these holes affect the structure of the building. You can close these entrance holes with wood, concrete, or hardware cloth (half-inch wire mesh aluminum screening).
To prevent the woodchucks from burrowing, dig a 1’ x 1’ foot trench around the base of the structure. Then nail the fencing to the bottom of the building, leaving enough at the bottom to bury underground (see diagram 1).
You might also try sliding a 3-foot wide chicken wire under the building about six inches (see diagram 2). When placed around all sides of the building, this fencing prevents the woodchuck from gaining access by digging. If the base of the building is more than 4 inches above the ground, also place vertical fencing around the building.
Woodchucks & Rabies
Good judgment will help eliminate the chances of people and wildlife coming in close contact with each other Woodchucks, like all mammals, can carry rabies.
Woodchucks & the Law
Relocating wildlife is illegal in Massachusetts. It is detrimental to the well-being of wildlife as well as the public.
Every year on February 2, Americans turn their attention to a small, furry animal. According to legend, if the groundhog (or woodchuck) sees his or her shadow there will be six more weeks of winter, but if not, spring is on the way.
The peculiarity of this tradition has earned it a beloved place in American folklore.
Upon coming to Pennsylvania in the 1700's, German settlers brought a longstanding tradition known as Candlemas Day—a holiday celebrated at the midpoint between the Winter Solstice and the Spring Equinox. Superstition held that if the weather was fair on Candlemas Day, the second half of winter would be stormy and cold. To determine the “forecast,” Germans watched a badger to check for a shadow.
Since there were no badgers in Pennsylvania, they looked for the next best thing—the groundhog.
Thus an American tradition began. According to the lore, if the groundhog sees his shadow, he regards it as an omen of six more weeks of bad weather and returns to his hole; if the day is cloudy, and therefore shadowless, he takes it as a sign of spring and stays above ground.
While the award for the most famous groundhog in America goes to Punxsutawney Phil from Pennsylvania, here in Massachusetts we have our own celebrity. Ms. G has been “forecasting” the weather at Drumlin Farm Wildlife Sanctuary in Lincoln since 2003.
In fact, Wellesley school students joined Mass Audubon in submitting a bill to the Massachusetts state legislature to declare Ms. G the Official State Groundhog. The bill was successfully enacted into law and signed by then Massachusetts Governor Deval Patrick on July 31, 2014.