Marmota monax

Woodchuck
(*Marmota monax*)
Woodchuck (Marmota monax)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Sciuromorpha
Family:	Sciuridae
Subfamily:	Xerinae
Tribe:	Marmotini
Genus:	Marmota
Subgenus:	Marmota (subgenus)
Binomial details
	Marmota monax (Linnaeus, 1758)
Other resources
	Full taxonomic details at MDD

The Woodchuck (Marmota monax) is the widest ranging of North American marmots.

Description

From Kwiecinski (1998): "Adult coloration does not differ between the sexes and varies from upperparts grayish- or reddish-brown (in M. m. ochracea vinaceous-cinnamon); head without white markings except around nose; sides of neck same colors as upper parts; feet black or dark brown; forelegs overlaid with deep reddish hairs (hazel to burnt sienna); tail black, dark brown, or pinkish cinnamon; wooly underfur confined to back and sides while longer guard hairs cover whole body; guard hairs with white tips yield frosted or grizzled appearance. Young are black then grayish and acquire adult pelage as yearlings (Howell, 1915)."

Museum specimens

Holotype: USNM 186521. Marmota monax rufescens. Adult male. Elk River, Sherburne County, Minnesota. Collected 9 April 1886.
Holotype: USNM 186521. Marmota monax rufescens. Adult male. Elk River, Sherburne County, Minnesota. Collected 9 April 1886.
Holotype: USNM 186521. Marmota monax rufescens. Adult male. Elk River, Sherburne County, Minnesota. Collected 9 April 1886.

External measurements

Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.

Part of range	Reference	Total length	Tail length	Hindfoot length	Ear length	Mass
Alabama	Best & Dusi (2014)	607 (560–636) (n=4)	114 (142–155) (n=4)	88 (82–94) (n=4)		2.7–3.0 kg (n=2)
Carolinas, Virginia, Maryland	Webster et al. (1985)	420–670	100–160			2.3–5.4 kg
Minnesota	Hazard (1982)	501–594	95–140	70–85	19–30	1,985–4,167
North Dakota	Seabloom et al. (2020)	536	117	78	27	4 kg
Virginia	Linzey (1998)	550–675 (head and body)	100–175			2.25–4.5 kg

Skull

Holotype: USNM 78360. Marmota monax rufescens. Adult male. Wilmington, Middlesex County, Massachusetts. Collected 19 April 1896. Dorsal view of the skull.
Holotype: USNM 78360. Marmota monax rufescens. Adult male. Wilmington, Middlesex County, Massachusetts. Collected 19 April 1896. Ventral view of the skull.
Holotype: USNM 78360. Marmota monax rufescens. Adult male. Wilmington, Middlesex County, Massachusetts. Collected 19 April 1896. Lateral view of the skull.
Holotype: USNM 78360. Marmota monax rufescens. Adult male. Wilmington, Middlesex County, Massachusetts. Collected 19 April 1896. Dorsal view of the mandible.
Holotype: USNM 78360. Marmota monax rufescens. Adult male. Wilmington, Middlesex County, Massachusetts. Collected 19 April 1896. Lateral view of the left mandible.

Comarison with Marmota caligata and Marmota flaviventris

From Kwiecinski (1998): "Of the North American marmots, M. monax (total length 418-665 mm) is smaller than M. flaviventris (470-700 mm) and M. caligata (533-820 mm). Tail is black or dark brown, bushy, almost flattened, and is short, being 20-25% total length. By contrast, in M. flaviventris the tail is 25-30% total length, and in M. caligata, 27-33% total length. Head is without the white markings (except around nose) that are present in congeners. Sides of the neck are the same color as upper parts, whereas M. flaviventris has conspicuous buffy patches. Ears are small, but larger than in congeners. Forelegs are overlaid with deep reddish brown hairs that are not present in congeners. Feet are black, blackish brown, or (in M. m. ochracea) pinkish cinnamon, but are buffy, hazel or tawny in M. flaviventris and either mixed black and white or solid brown in M. caligata. Posterior pad on sole of hind foot is oval in shape and situated near the middle of the sole, similar to M. flaviventris, whereas that of M. caligata is near the edge of the sole."

Woodchuck (Marmota monax) photographed by sfreeman7 in Toronto, Ontario, Canada.
Hoary Marmot (Marmota caligata) photographed by Eemeli Haverinen in Denali National Park, Alaska.
Yellow-bellied Marmot (Marmota flaviventris) photographed by Rick Overson in Custer Gallatin National Forest, Montana.
Ventral surface of sole of hind foot of the Yellow-bellied Marmot (Marmota flaviventris), showing oval shape of posterior pad, which is similar to the posterior pad in the Woodchuck (Marmota monax). Borrowed from Frase and Hoffman (1980).

References

Best TL, Dusi JL. 2014. Mammals of Alabama (Vol. 4). Tuscaloosa (AL, USA): University Alabama Press.

Hazard EB. 1982. The mammals of Minnesota. Minneapolis (MN, USA): University of Minnesota Press.

Howell AH. 1915. Revision of the American marmots. United States Department of Agriculture Bureau of Biological Survey, North American Fauna 37:1-80.

Kwiecinski GG. 1998. Marmota monax. Mammalian Species (591):1-8.

Linzey DW. 1998. The mammals of Virginia. McDonald & Woodward Publishing.

Seabloom R, Hoganson JW, Jensen WF. 2020. The mammals of North Dakota. Fargo (ND, USA): North Dakota State University Press.

Webster WD, Parnell JF, Biggs WC. 1985. Mammals of the Carolinas, Virginia, and Maryland. Chapel Hill (NC, USA): University of North Carolina Press.