Woodchucks, also known as groundhogs or whistle-pigs, are a member of the squirrel family and reside throughout the Eastern and Midwestern sections of the United States and throughout most of Canada. Their name is derived from their Algonquin name wuchak and has nothing to do with wood. In the wild woodchucks live an average of six years, while in captivity they have lived up to 14 years. Woodchucks produce one litter of two to six “kits” annually in late April or early May. By August, the kits leave their mother and begin preparing for hibernation. While hibernating, a woodchuck’s body temperature drops from 99°F to 40°F, and her heartbeat drops from 100 beats per minute to 4 beats per minute.
They are excellent diggers and live in complex underground systems of burrows. There is usually a main entrance distinguished by a mound of soil around it, and several secondary entryways that are often used as escape doors. Burrows are often near rocks, tree roots, or other supportive structures that help to prevent predators from gaining access to them. Many woodchucks share their burrows with other animals, and use the burrows for hibernation for about six months every winter. Woodchucks are vegetarians and can often be seen grazing near the edges of fields and roadways.
POSSIBLE CONFLICTS & SOLUTIONS
Woodchucks leave a clean cut on plants that they browse, unlike the jagged edges of plants browsed by deer. As a result of their browsing, they often cause trouble for gardeners. They can be deterred by attaching a motion sensor to a garden hose; using novel stimuli like scarecrows, balloons, and pinwheels; or leaving a beach ball within the area they are disturbing and letting it blow in the wind. Visiting your garden often and mowing long grasses can also help. Specific plants can be protected by sprinkling them with Epsom salts (reapply after every rain) or by covering them with fabric or gallon jugs with the bottoms removed. You can also try placing rags soaked in ammonia on posts placed at intervals around the perimeter of the garden. The odor is enough to deter most unwanted visitors. The rags must be re-soaked when the smell of ammonia fades and after each rain. Note that ammonia fumes can harm animals’ lungs, so don’t use it closer than two feet from where animals may be, especially when babies may be present.
The most effective means of ridding small gardens of hungry woodchucks is to install at least 3– to 4- foot-high wire fencing around the perimeter of the garden, burying it at least one foot underground with an outward bend in an L-shape. Woodchucks are proficient at digging and have no trouble going under a fence that is not deep in the ground. Making sure the fence is somewhat loose and not pulled taut will make it more difficult for an interested groundhog to climb up it. If you have persistent visitors to your garden, a single strand of electric fencing in front of the fence 4 to 5 inches high will give your garden an extra level of protection.
Woodchuck burrows can sometimes cause problems for homeowners if they are under buildings or too close to gardens. In these cases, it is best to try and harass the woodchucks out, and then permanently exclude them from getting back into the burrow.
Before doing so, listen for noises that will indicate the presence of young, such as squeaking, whining, and rustling. Remember not to touch or approach any young animals you find, as your scent may deter the mother from returning and claiming her young. If young are present, please tolerate them until they are old enough to accompany the adults out of the burrow.
If tolerance is impossible, removing ground cover around the burrows and partially digging out the entryways can help to encourage the mother to take her young and move on. If these harassment techniques do not work, try using commercially available repellants to encourage the woodchucks to go elsewhere.
As a last resort, in a well-ventilated area, pour a small amount of ammonia on a rag and place the rag in a plastic bag. Place the bag at least two feet from the entrance to the burrow and to the side of the entrance. Do not put the rag closer than two feet from the entrance and do not put it directly in front of the entrance, as the ammonia fumes could injure any woodchucks who may be inside the burrow. It is important to never use toxic substances like gasoline to try to get woodchucks or other burrow inhabitants to leave, as they are inhumane and toxic to both people and animals.
Once it is certain that there are no young present, a one-way door can be used to permanently evict woodchucks from burrows. Check for inhabitants by loosely placing hay or grass into the entrance and see if it is displaced the next day.
Next, you will need to permanently seal off the burrow to prevent other wildlife from moving in. To seal off the burrow, excavate the area around the entrance, and bury 3-square-foot pieces of heavy-gauge welded wire at least a foot deep around the entrance. As woodchucks are such great diggers, the wire should extend well past the burrow entrance on all sides. After sealing off a burrow entrance, it is a good idea to observe the area and make sure that no new woodchucks are trying to gain access.
PUBLIC HEALTH CONCERNS
Woodchucks are not a significant source of infectious diseases transmittable to humans. As with all mammals, they can contract rabies, and may become very aggressive in the final stages of the disease.