Groundhog (Marmota monax)

MammalRodentNorth America

Overview

The groundhog (Marmota monax), also called the woodchuck, is a large, heavy-bodied ground squirrel of North America and one of the biggest members of the squirrel family. It is a marmot — a group of stout, burrowing rodents mostly associated with mountains, though the groundhog is a lowland exception.

Groundhogs are chunky and short-legged, with coarse grizzled brown fur, small ears and strong claws suited to digging. They are far more solitary than prairie dogs and far more strongly tied to a single burrow system.

Unlike chipmunks, which rouse through winter to feed on stored food, the groundhog is a true hibernator: it fattens heavily in late summer and autumn, then sleeps through winter on its body reserves with a deeply lowered body temperature and heart rate.

Habitat & Range

Groundhogs live across much of eastern and central North America, from the eastern United States north into Canada and Alaska. They favour woodland edges, hedgerows, meadows, pasture and roadside banks — places where open feeding ground meets cover. Burrows are extensive, with several entrances, separate chambers, and a distinct winter chamber below the frost line.

Diet

Groundhogs are herbivores, feeding on grasses, clover, dandelions, plantain, garden vegetables, fruit and the leaves and bark of some woody plants. Feeding is concentrated in the growing season, and animals put on substantial fat reserves before entering hibernation.

Behavior

Groundhogs are diurnal, largely solitary outside the breeding season, and closely tied to their burrows, rarely straying far from an entrance. They sit up on their haunches to scan for danger and give a sharp whistle when alarmed — the origin of the nickname 'whistlepig'. Despite their bulk they climb trees and swim when they need to. Abandoned groundhog burrows are used by many other animals, from foxes and skunks to rabbits and snakes.

Human Interaction & Conservation

The groundhog is best known outside biology through Groundhog Day, a North American folk tradition with no predictive value for weather. In practical terms groundhogs are often in tension with gardeners and farmers because of their feeding and digging. This profile is educational only and gives no wildlife-control, trapping or handling guidance; such questions should go to local wildlife authorities. The species is common and widespread; verify current status at the IUCN Red List.

Sourced facts

Each value below is traced to the specific reference that states it. Open a row's evidence to see the source, where to look in it, and how firmly it supports the value. Sources checked 2026-10-09.

Sourced facts about the Groundhog, with the reference supporting each
Fact	What the source states	Evidence
Geographic range	The most widespread North American marmot: south to eastern Oklahoma, northern Louisiana, Alabama and Georgia; east along the Atlantic coast to Labrador; north from Labrador to southern Alaska.Biogeographic region tag: Nearctic (native).	Matches source · Animal Diversity Web — how we know Animal Diversity Web — University of Michigan Museum of Zoology Where Geographic Range Checked by FaunaHub 2026-10-09 Limits A peer-edited account written largely by students under faculty review. Figures are compiled from the literature rather than from a single study, and some are regional.
Habitat	Low-elevation forests, small woodlots, fields, pastures and hedgerows; digs dens in well-drained soil, most with a summer den near food and a winter den near protective cover.ADW adds that forest clearing, road building and agriculture have increased food access and abundance, 'allowing M. monax to thrive'. Habitat tags include suburban, agricultural and riparian. No elevation figure is given (only 'low elevation').	Matches source · Animal Diversity Web — how we know Animal Diversity Web — University of Michigan Museum of Zoology Where Habitat Checked by FaunaHub 2026-10-09 Limits A peer-edited account written largely by students under faculty review. Figures are compiled from the literature rather than from a single study, and some are regional.
Diet	Mainly plants: preferred forage is alfalfa, clover and dandelion; other foods include bark, leaves, insects and bird eggs. Stores fat for winter hibernation.ADW's primary-diet tags are herbivore and folivore; animal foods tagged are eggs, insects and mollusks.	Matches source · Animal Diversity Web — how we know Animal Diversity Web — University of Michigan Museum of Zoology Where Food Habits Checked by FaunaHub 2026-10-09 Limits A peer-edited account written largely by students under faculty review. Figures are compiled from the literature rather than from a single study, and some are regional.
Body size	Total length 415 to 675 mm, of which the tail is 100 to 160 mm; males are larger than females.Total length including the tail. ADW also says the tail is 20 to 25% of total body length. No sex-specific measurements are given.	Matches source · Animal Diversity Web — how we know Animal Diversity Web — University of Michigan Museum of Zoology Where Physical Description Checked by FaunaHub 2026-10-09 Limits A peer-edited account written largely by students under faculty review. Figures are compiled from the literature rather than from a single study, and some are regional.
Body mass	2 to 6 kg; males are larger than females.ADW gives no sex-specific masses and no seasonal (pre-/post-hibernation) figures. Newborn pups weigh 26 to 27 g (Reproduction).	Matches source · Animal Diversity Web — how we know Animal Diversity Web — University of Michigan Museum of Zoology Where Physical Description Checked by FaunaHub 2026-10-09 Limits A peer-edited account written largely by students under faculty review. Figures are compiled from the literature rather than from a single study, and some are regional.
Lifespan	Wild: typically 4 to 6 years (range 2 to 6), often not past age 3. Captivity: up to 10 years, with one source giving an average of 14.sources disagreeThe text also says 'Woodchucks may live up to 10 years in captivity.'	Sources disagree · Animal Diversity Web — how we know What each reading says 4 to 6 years — Animal Diversity Web, wild, typical 2 to 6 years — Animal Diversity Web, wild, range; often not past age 3 up to 10 years — Animal Diversity Web, captivity, maximum 14 years — Animal Diversity Web, captivity 'average', AnAge (cited in ADW data table) Captive figures only: ADW gives a captive maximum of 10 years (text 'up to 10 years'; table '10 (high)') but also cites AnAge for an average captive lifespan of 14 years. An average cannot exceed the maximum. The wild figures (typical 4-6, range 2-6) are consistent. Animal Diversity Web — University of Michigan Museum of Zoology Where Lifespan/Longevity Checked by FaunaHub 2026-10-09 Limits A peer-edited account written largely by students under faculty review. Figures are compiled from the literature rather than from a single study, and some are regional.
Activity pattern	Diurnal, with feeding highest in the morning and afternoon. A true hibernator over most of its range, but in the south it has been known to stay active all year.The first excerpt is from Food Habits. ADW also says they may enter torpor during the day at certain times of year and often sun themselves at midday in summer. Its key-behaviour tags list crepuscular alongside diurnal, but the prose describes only daytime activity.	Matches source · Animal Diversity Web — how we know Animal Diversity Web — University of Michigan Museum of Zoology Where Behavior Checked by FaunaHub 2026-10-09 Limits A peer-edited account written largely by students under faculty review. Figures are compiled from the literature rather than from a single study, and some are regional.
Social structure	Non-social outside the mating season. Dominant males' home ranges overlap those of at least 2 females, while subordinate males are nomadic.The first excerpt is from Reproduction. ADW calls the mating system polygynous, says older, dominant males hold territories and younger males are nomadic, lists territoriality and dominance hierarchies, and notes that woodchucks sometimes greet each other nose to nose. Only females care for the young.	Matches source · Animal Diversity Web — how we know Animal Diversity Web — University of Michigan Museum of Zoology Where Behavior Checked by FaunaHub 2026-10-09 Limits A peer-edited account written largely by students under faculty review. Figures are compiled from the literature rather than from a single study, and some are regional.
Conservation status	Least Concern (LC), global assessment, 2016	Matches source · IUCN Red List of Threatened Species — how we know IUCN Red List of Threatened Species Checked by FaunaHub 2026-10-09 Limits Read from the Red List export IUCN publishes to GBIF; iucnredlist.org itself does not answer automated reads. Categories are reassessed over time.

References for the facts above

UniversityAnimal Diversity Web — University of Michigan Museum of ZoologySupports: Range, habitat, diet, body size and mass, lifespan, activity and social structure, as the account states them. Retrieved 2026-10-09.Limitations: A peer-edited account written largely by students under faculty review. Figures are compiled from the literature rather than from a single study, and some are regional.
ReferenceIUCN Red List of Threatened SpeciesSupports: The global Red List category and the year of the assessment. Retrieved 2026-10-09.Limitations: Read from the Red List export IUCN publishes to GBIF; iucnredlist.org itself does not answer automated reads. Categories are reassessed over time.

Frequently Asked Questions — Groundhog

Is a groundhog the same as a woodchuck?

Yes — two names for the same animal, Marmota monax. 'Woodchuck' has nothing to do with wood or chucking; it is generally traced to an Algonquian name for the animal that English speakers reshaped into familiar words.

Do groundhogs really hibernate?

Yes. The groundhog is a true hibernator, which sets it apart from chipmunks. It builds heavy fat reserves in late summer and autumn, retreats to a winter chamber below the frost line, and passes the winter with a greatly lowered body temperature, heart rate and breathing rate.

What do groundhogs eat?

They are herbivores. The diet is mainly grasses, clover, dandelions and other soft green plants, along with fruit, garden vegetables and some bark and leaves of woody plants. They feed heavily through the growing season to build the fat they need for winter.

Are groundhogs related to prairie dogs?

Yes — both are burrowing ground squirrels in the family Sciuridae. Groundhogs are marmots and are typically solitary, tied to one burrow system, whereas prairie dogs are smaller and live in large social colonies.

Sources and further reading

Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.

UniversityAnimal Diversity Web — Marmota monax (woodchuck) — University of Michigan species account
Wildlife referenceSmithsonian's National Zoo & Conservation Biology Institute — Animals — Educational species pages from the Smithsonian Institution
ReferenceEncyclopaedia Britannica — Animals reference — Editor-reviewed encyclopedia overview entries