Woodchuck Marmota monax

Head and body length of M.monax is between 300-600 mm, tail length is 100-250 mm. Adults weigh between 3.0 - 7.5 kg. Overall coloration ranges from brown to brownish black. The fur varies in coarseness and thickness due to geographical location and season.

M.monax prefers alpine meadows, forest edge and pastures, building burrows in well-drained soil. These burrows may have several entrances and are usually excavated at about 1 meter deep. Hibernation burrows, however, are built from 5-7 meters below the surface with tunnels as long as 70 meters. Woodchucks build two dens: one for summer which is located in a flat, open or gently rolling area, with an entrance distinguished by a mound of earth; and a winter den, generally on a slope in a wooded area. M.monax is mainly terrestrial and diurnal, but sometimes climbs into trees or shrubs.

Depending on its location, M.monax hibernates between 6-8 weeks in the southern part of its range and up to 9 months in the north. During deep hibernation, Woodchucks live on the fat it has stored up throughout the summer, which can be as much as 20% of its body weight. The diet consists of green vegetation, especially grasses and forbs, but can include fruits, grains, legumes, and insects.

Woodchucks are solitary, and usually only come together at a particularly good feeding site, or during breeding. Young are evicted from the nest at about 6 weeks. The young are born in a grass lined nest after a gestation period of 30-32 days. Mating season occurs once each year, usually shortly after emerging from hibernation.

M.monax has adapted easily to human development and is considered a pest in most of its range. It can do severe damage to crops and the burrows it builds are hazardous to farm machinery and livestock. The range of M.monax is from Alaska (USA) through S Canada to S Labrador to NE and SC USA; south in the Rocky Mtns, possibly to N Idaho.