The Carlisle Mosquito Online

Friday, February 2, 2007


Groundhog (Marmota monax)

(Joan saw these groundhogs — and their shadows — early last summer, but the Mosquito asked her to save their story until Groundhog Day.)

This mother and her two babies were spotted last summer near the Bedford town line, looking for a snack. (Photo by Joan Rolfe)

Groundhogs or Marmota monax are also known as woodchucks and marmots. Surprisingly, they are also members of the squirrel (Sciuridae) family, having four toes on their front feet and five on the back, with a prominent bushy tail. The woodchuck name comes from Cree Indian word "wuchak" which is also used for many similar mammals. Of the five North American species in the genus Marmota, the groundhog is the most widely dispersed. It is found in east-central Alaska, most of Canada, and the eastern and central United States.

"Woodies" are heavy-bodied, with short legs and a reddish or yellowish-brown to brown fur coat, and a lighter belly. The fur tips may show a "frosted" look. The feet are dark brown or black, and there may be a little white around the nose. They resemble beavers and muskrats, except for the size and tail.

Family life

This mother and her two babies were seen in Carlisle near the Bedford line, in a lovely yard with many stone walls, plants and trees, and birdfeeders where they could eat a handy snack. The adorable little ones were probably born sometime in April or May, with the mother having just one litter annually, two to five young. The male briefly visits a receptive female's den for mating — the only time two adults share a den. The gestation period is 31 to 32 days and the young are born naked and blind, opening their eyes and moving about at one month and then leaving the den in about two months. The probable "Dad" would occasionally surface, sunning himself on one of the large landscaping rocks, but was not seen socializing much with his family.

Usually the woodchuck is active at night, but the sun-loving family shown here was seen going about in the daytime, probably because of an abundant source of birdseed in a very safe hidden yard. They also like to munch on tender and juicy plants, much to the landscapers' and vegetable gardeners' chagrin. Many interesting devices and fences have been created to keep these wily and hungry creatures out.

Where they live

Woodchucks nest in burrows or dig beneath rocks or logs. Woodpiles (abundant in Carlisle) are favorite hiding and nesting places. They also live in open woods, bush, pastures and meadows, and rocky ravines. Woodchucks are good climbers and swimmers and will quickly go up a tree to escape enemies or seek a vantage point, but they don't like to wander far from their den. To spy on their surroundings, they often sit up on their haunches like a "picket pin." When alarmed, they give a loud, sharp whistle and chatter their teeth when agitated. They also hiss, squeal and growl. Major enemies are hunters, cars, and large predators such as the Red Fox.

The burrowed den may be up to five feet deep and anywhere from 25-30 feet long and have two or more openings which may or may not have a telltale pile of excavated dirt. The home range of the woodchuck may be as large as 40-160 acres.

Hibernation time

Preparing for hibernation, woodchucks put on a heavy layer of fat during late summer or early fall. They dig a winter burrow terminating in a hibernation chamber where they curl up on matted grasses. Considered a true hibernator, "Woody's" body temperature falls from 97° to less than 40°. Breathing slows to once every six minutes, and the normal heartbeat of 100 beats a minute goes to only four a minute. Hibernation typically begins around October and lasts until February.

Sources: A Field Guide to the Mammals, William H. Burt & Richard P. Grossenheider (sponsored by National Audubon Society and National Wildlife Federation); National Audubon Society — Field Guide to North American Mammals, John O. Whitaker, Jr., Professor of Life Sciences, Indiana State University.

2007 The Carlisle Mosquito