E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Marmota monax (Linnaeus, 1758
Groundhog; Woodchuck
Family: Sciuridae
Photo of species

© Larry Halverson  Email the photographer   (Photo ID #127779)

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Distribution of Marmota monax in British Columbia
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Species Information

Groundhogs are part of the group of large ground squirrels known as marmots. The Groundhog is the smallest species of marmot found in British Columbia. It typically measures 40 to 65 cm (17 to 26 in) long (including a 15 cm tail) and weighs 2 to 4 kg (4.5 to 9 pounds). In areas with fewer natural predators and large quantities of alfalfa, groundhogs can grow to 80 cm (32 in) and 14 kg (30 lb). Groundhogs are well adapted for digging, with short but powerful limbs and curved, thick claws. Unlike other sciurids, the groundhog's spine is curved, more like that of a mole, and the tail is comparably shorter as well – only about one-fourth of body length. Suited to their temperate habitat, groundhogs are covered with two coats of fur: a dense grey undercoat and a longer coat of banded guard hairs that gives the groundhog its distinctive "frosted" appearance.

Biology


Groundhogs usually live from two to three years, but can live up to six years in the wild. In captivity, groundhogs can exceed this limit; by example, the 22-year-old Wiarton Willie may indicate the maximum lifespan. Young groundhogs are often at risk for predation by snakes, which easily enter the burrow.
Reproduction

Usually groundhogs breed in their second year, but a small proportion may breed in their first. The breeding season extends from early March to mid- or late April, after hibernation. A mated pair remains in the same den throughout the 28-32 day gestation period. As birth of the young approaches in April or May, the male leaves the den. One litter is produced annually, usually containing 2-6 blind, hairless and helpless young. Young groundhogs are weaned and ready to seek their own dens at five to six weeks of age.
Diet

Mostly herbivorous, groundhogs primarily eat wild grasses and other vegetation, and berries and agricultural crops when available. Groundhogs also eat grubs, grasshoppers, insects, snails and other small animals, but are not as omnivorous as many other sciurids.
Behaviour

Groundhogs are excellent burrowers, using burrows for sleeping, rearing young, and hibernating. The average groundhog has been estimated to move approximately 1 m³ (35 cubic feet), or 320 kg (700 pounds), of dirt when digging a burrow. Though groundhogs are the most solitary of the marmots, several individuals may occupy the same burrow. Groundhog burrows usually have two to five entrances, providing groundhogs their primary means of escape from predators. Burrows are particularly large, with up to 45 feet (14 m) of tunnels buried up to 5 feet (1.5 m) underground, and can pose a serious threat to agricultural and residential development by damaging farm machinery and even undermining building foundations.

Groundhogs are one of the few species that enter into true hibernation, and often build a separate "winter burrow" for this purpose. This burrow is usually in a wooded or brushy area and is dug below the frost line and remains at a stable temperature well above freezing during the winter months. In most areas, groundhogs hibernate from October to March or April, but in more temperate areas, they may hibernate as little as 3 months. To survive the winter, they are at their maximum weight shortly before entering hibernation. They emerge from hibernation with some remaining body fat to live on until the warmer spring weather produces abundant plant materials for food.

Outside their burrow, individuals are alert when not actively feeding. It is common to see one or more nearly-motionless individuals standing erect on their hind feet watching for danger. When alarmed, they use a high-pitched whistle to warn the rest of the colony. Groundhogs may squeal when fighting, seriously injured, or caught by an enemy. Other sounds groundhogs may make are low barks and a sound produced by grinding their teeth.
Predators

Predators include the Coyote, Red Fox and Bocat, plus raptors.

Habitat


The groundhog is found in lowland areas, and prefers open country and the edges of woodland. It is rarely found far from a burrow entrance.

Distribution

Global Range

Groundhogs are widely distributed in North America and common in the northeastern and central United Sates, and across Canada. They are found as far north as Alaska, and southeast to Alabama.
Distribution in British Columbia

In British Columbia, this species is found in the Columbia Mountains, southern Rocky Mountains, and most of the central and northern interior; it is generally absent from coastal areas, although there are a few records from the Coast Mountains, it is absent from much of the dry grasslands of the central interior.

Taxonomy


Nine subspecies of Groundhogs are recognized in North America: three occur in British Columbia. 1) Marmota monax canadensis (Peace River and Fort Nelson lowlands), 2) Marmota monax ochracea (extreme north-central and northwestern parts of BC) 3) Marmota monax petrensis (southeastern and central BC).

Comments


Melanism is common in BC Groundhogs, and in some parts of the province black animals are more common than brown ones. Groundhogs steadily increase in weight.throughout the summer, accumulating heavy fat deposits. Hibernation begins at the beginning of October. They usually hibernate alone.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
NativeS5YellowNot Listed
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Photo Sources

Species References

Nagorsen, David W. 2005. Rodents and Lagomorphs of British Columbia. Royal BC Museum Handbook. Royal BC Museum, Victoria.

General References


Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2022-01-26 11:42:27 PM]
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