Search Field Guide
Advanced Search
MT Gov Logo
Montana Field Guide

Montana Field Guides

Hoary Marmot - Marmota caligata

Potential Species of Concern
Native Species

Global Rank: G5
State Rank: S3S4

Agency Status

External Links

General Description
The hoary marmot is a large, stocky rodent about 70 cm in total length and 5 kg in weight. Its head is broad and round with small, well-furred ears, and its neck is short. Its feet have strong claws, as well as nearly circular pads on the hind feet which distinguish it from other marmots. Its long tail makes up nearly a third of its total length. Fur is coarse, with many white-tipped guard hairs rendering a grizzled appearance; hence, the name “hoary”. The head and front third of the body are usually black, as are the feet, and the belly is lighter in color. (Foresman 2012)

Diagnostic Characteristics
Can be distinguished fairly readily from Montana’s other marmot, the yellow-bellied marmot, based on color; the hoary marmot is whitish gray and grizzled, whereas the yellow-bellied marmot is, as its name suggests, yellowish brown to tawny with a distinctly yellow belly. The hoary marmot is the larger of the two species. Where their ranges overlap, hoary marmots are found in alpine habitats and yellow-bellied marmots at lower elevations. (Foresman 2012)

Species Range
Montana Range Range Descriptions


Western Hemisphere Range


Observations in Montana Natural Heritage Program Database
Number of Observations: 961

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)


Occupies alpine and subalpine habitats, with burrows in rock outcrops, boulder fields, or talus slopes adjacent to meadows.

Ecological Systems Associated with this Species
  • Details on Creation and Suggested Uses and Limitations
    How Associations Were Made
    We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
    1. Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
    2. Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
    3. Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
    4. Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
    Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.  In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.  However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if point observations were associated with that system.  Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.  The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.  If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.

    Suggested Uses and Limitations
    Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.  These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.  Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.  Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.  Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).  Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.

    Literature Cited
    • Adams, R.A.  2003.  Bats of the Rocky Mountain West; natural history, ecology, and conservation.  Boulder, CO: University Press of Colorado.  289 p.
    • Dobkin, D. S.  1992.  Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34.  Missoula, MT.
    • Foresman, K.R.  2012.  Mammals of Montana.  Second edition.  Mountain Press Publishing, Missoula, Montana.  429 pp.
    • Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998.  Montana atlas of terrestrial vertebrates.  Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT.  1302 p.
    • Hutto, R.L. and J.S. Young.  1999.  Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32.  72 p.
    • Maxell, B.A.  2000.  Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species.  Report to U.S. Forest Service Region 1.  Missoula, MT: Wildlife Biology Program, University of Montana.  161 p.
    • Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath.  2004.  Amphibians and reptiles of Montana.  Missoula, MT: Mountain Press Publishing Company. 262 p.

Food Habits
A diurnal herbivore that is fairly selective in the plants that it eats. In Montana, hoary marmots eat many flowering species, including silky lupine, Indian paintbrush, and glacier lily, as well as grasses and sedges (Foresman 2012).

Highly social (Braun et al. 2011). Colonies are typically made up of one adult male, one or more adult females, yearlings, and young-of-the-year (Foresman 2012). At two years of age, offspring disperse from the natal colony. Colonies maintain separate burrows for hibernation, sleeping, and refuge from predators (Braun et al. 2011).

Spends the majority of its life hibernating. In Montana, hoary marmots hibernated from September to early May (Foresman 2012).

May be able to outcompete Marmota flaviventris in high-elevation habitats (Hoffman 1974).

Reproductive Characteristics
Immediately after marmots emerge from hibernation, reproductive activity begins. Gestation is about 30 days, with an average litter size of 2-4. Females tend to reproduce every other year. Both males and females are sexually mature at 3 years of age. (Foresman 2012)

Marmot populations are vulnerable to climate change for several reasons: their physiology is adapted to low temperatures, and they are stressed by high heat loads; warming temperatures are associated with drier, unpalatable vegetation; and drought reduces reproduction and increases mortality, meaning that reductions in summer rainfall could lead to local extinctions. Species like the hoary marmot that live in high alpine areas are most vulnerable, as they have little opportunity to move farther upslope with warming conditions. (Armitage 2013)

Login Logout
Citation for data on this website:
Hoary Marmot — Marmota caligata.  Montana Field Guide.  .  Retrieved on , from