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BC Conservation Data Centre: Species Summary


Ondatra zibethicus
Common Muskrat

 
Scientific Name: Ondatra zibethicus (Linnaeus, 1766)
English Name: Common Muskrat
 
Classification / Taxonomy
Scientific Name - Concept Reference: Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/.
Classification Level: Species
Species Group: Vertebrate Animal
Species Code: M-ONZI
Kingdom Phylum Class Order Family
Animalia Craniata Mammalia Rodentia Cricetidae
   
Conservation Status / Legal Designation
Global Status: G5 (Aug 2024)
Provincial Status: S5 (Mar 2024)
BC List: Yellow
Provincial FRPA list:   
Provincial Wildlife Act:
COSEWIC Status:
SARA Schedule:
General Status Canada: 4 - Secure (2005)
   
Ecology & Life History
General Description:
Global Reproduction Comments: Gestation lasts 28-30 days. Average of 2-3 litters/year. Litter size is 1-12 (usually averages about 5-6). Weaned and fairly independent after about 1 month. Sexually mature in 4-6 months. In Saskatchewan, polygyny was common (Marinelli and Messier 1993). Typically high rate of mortality in young.
Global Ecology Comments: Generally solitary but several may use same general area; in winter several may congregate in single den. Territoriality common (Caire et al. 1989), mostly in breeding season.

Home range sizes relatively small; usually does not forage more than 11 m from home site (Baker 1983). In marginal areas, foraging excursions greater. Seasonal home range may range from less than 0.1 ha to several hectares (see Marinelli and Messier 1993). Home ranges generally less than 100 m in diameter (Takos 1944, Boutin and Birkenholz 1987). However, along linear waterways, home ranges average 411 meters long (Willner et al. 1980).

Populations fluctuate, density up to about 90/ha, usually much less (6/ha, 24/ha, and 36/ha in three studies cited by Marinelli and Messier 1993).

In Manitoba, spatial and temporal variation in vegetation response to flooding contributed to variation in the density dependence of both survival and recruitment; reductions in emergent vegetation caused by flooding resulted in decreased winter survival (Clark and Kroeker 1993).
Migration Characteristics:
(Global / Provincial)		 
    Nonmigrant:
    Local Migrant:
    Distant Migrant:
    Within Borders Migrant: 		Y /
N /
N /
na /
Habitats:
(Type / Subtype / Dependence) 		Lakes / Lake / Facultative - frequent use
Lakes / Pond/Open Water / Facultative - frequent use
Other Unique Habitats / Estuary / Facultative - frequent use
Riparian / Riparian Forest / Facultative - occasional use
Riparian / Riparian Herbaceous / Facultative - frequent use
Riparian / Riparian Shrub / Facultative - occasional use
Stream/River / Stream/River / Facultative - frequent use
Wetland / Bog / Obligate
Wetland / Fen / Obligate
Wetland / Marsh / Obligate
Wetland / Swamp / Obligate
Global Habitat Comments: Prefers fresh or brackish marshes, lakes, ponds, swamps, and other bodies of slow-moving water. Most abundant in areas with cattail. Rare or absent in large artificial impoundments where fluctuating water levels eliminate littoral zone plants (food supply) (Caire et al. 1989). Dens in bank burrow or conical house of vegetation in shallow vegetated water. Sometimes in uplands-Clough 1987.

See Clark (1994) for information on habitat selection in experimental marshes undergoing succession in Manitoba.
Food Habits: Herbivore: Adult, Immature
Invertivore: Adult, Immature
Global Food Habits Comments: Diet mainly consists of aquatic plants, particularly cattails (TYPHUS spp.), cordgrass, and bulrush. Also eats crustaceans and mollusks; may eat large numbers mussels in some areas (Hanson et al. 1989). Builds rooted feeding platforms. Eats mainly upland vegetation in some areas.
Global Phenology: Circadian: Adult, Immature
Crepuscular: Adult, Immature
Nocturnal: Adult, Immature
Global Phenology Comments: Mainly nocturnal but frequently seen in daylight. Active year-round. Two peaks of activity: between 1600 and 1700 h and 2200-2300 hours (Stewart and Boder 1977).
Provincial Phenology:
(1st half of month/
2nd half of month)
Colonial Breeder: N
Length(cm)/width(cm)/Weight(g): 62/ / 1816
Elevation (m) (min / max): Global: 
Provincial: 
   
 
Distribution
Endemic: N
Global Range Comment: This species occurs in North America, north to the treeline, including Newfoundland, Canada; south to the Gulf Coast, Rio Grande, and lower Colorado River valleys, U.S.A.; introduced and now widespread in Eurasia as well as Argentina.
 
Authors / Contributors
Global Information Author: Hammerson, G.
Last Updated: Dec 13, 1994
Provincial Information Author:
Last Updated:
   
References and Related Literature
Baker, R. H. 1983. Michigan mammals. Michigan State University Press. 642 pp.
Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, Canada. 438 pp.
Caire, W., J. D. Tyler, B. P. Glass, and M. A. Mares. 1989. Mammals of Oklahoma. University of Oklahoma Press, Norman. Oklahoma. 567 pp.
Clark, W. R. 1994. Habitat selection by muskrats in experimental marshes undergoing succession. Can. J. Zool. 72:675-680.
Clark, W. R., and D. W. Kroeker. 1993. Population dynamics of muskrats in experimental marshes at Delta, Manitoba. Can. J. Zool. 71:1620-1628.
Clough, G. C. 1987. Ecology of island muskrats, Ondatra zibethicus, adapted to upland habitat. Can. Field-Nat. 101:63-69.
Errington, P.L. 1961. Muskrats and marsh management. Stackpole Co., Harrisburg, PA. 183 pp.
Errington, P.L. 1963. Muskrat populations. Iowa State Univ. Press, Ames. 665 pp.
Godin, A. J. 1977. Wild mammals of New England. Johns Hopkins University Press, Baltimore. 304 pp.
Hall, E. R. 1981a. The Mammals of North America, second edition. Vols. I & II. John Wiley & Sons, New York, New York. 1181 pp.
Hamilton, W. J., Jr., and J. O. Whitaker, Jr. 1979. Mammals of the eastern United States. Cornell Univ. Press, Ithaca, New York. 346 pp.
Hanson, J. M., W. C. Mackay, and E. E. Prepas. 1989. Effect of size-selective predation by muskrats (Ondatra zibethicus) on a population of unionid clams (Anodonta grandis simpsoniana). J. Anim. Ecol. 58:15-28.
Hollister, N. 1911. A systematic synopsis of the muskrats. North American Fauna 32:1-47.
Johnson, C.E. 1925. The muskrat in New York: Its natural history and economics. Roosevelt Wildlife Bull., 3(2):205- 320.
Marinelli, L., and F. Messier. 1993. Space use and the social system of muskrats. Can. J. Zool. 71:869-875.
Nagorsen, D. W. 2005b. The rodents and lagomorphs of British Columbia. Royal B.C. Mus. Handb., Victoria, BC. 410pp.
Neves, R. J., and M. C. Odom. 1989. Muskrat predation on endangered freshwater mussels in Virginia. J. Wild. Manage. 53:934-941.
Perry, H. R., Jr. 1982. Muskrats (Ondatra zibethicus and Neofiber alleni). Pages 282-325 in J. A. Chapman and G. A. Feldhamer, editors. Wild mammals of North America. Johns Hopkins Univ. Press, Baltimore.
Schwartz, C. W., and E. R. Schwartz. 1981. The wild mammals of Missouri. University of Missouri Press, Columbia. 356 pp.
Stewart, R.W. and J.R. Boder. 1977. Summer activity of muskrats in relation to weather. J. Wildl. Mgmt. 41:487-499.
Willner, G. R., G. A. Feldhammer, E. E. Zocker, and J. A. Chapman. 1980. Ondatra zibethicus. American Society of Mammalogists, Mammalian Species No. 141. 8 pp.
Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/.
 

Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.

Suggested Citation:

B.C. Conservation Data Centre. 1994. Species Summary: Ondatra zibethicus. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed May 13, 2026).