Species: Ondatra zibethicus
Common Muskrat
Species
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Encyclopedia of Puget Sound

Classification
Kingdom
Animalia
Phylum
Craniata
Class
Mammalia
Order
Rodentia
Family
Cricetidae
Genus
Ondatra
NatureServe
Classification
Other Global Common Names
Muskrat - rat musqué
Informal Taxonomy
Animals, Vertebrates - Mammals - Rodents
Formal Taxonomy
Animalia - Craniata - Mammalia - Rodentia - Cricetidae - Ondatra
Ecology and Life History
Migration
true - false - false
Non-migrant
true
Locally Migrant
false
Food 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.
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.
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. <br><br>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). <br><br>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). <br><br>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).
Length
62
Weight
1816
Conservation Status
NatureServe Global Status Rank
G5
Global Status Last Reviewed
1996-11-13
Global Status Last Changed
1996-11-13
Other Status
LC - Least concern
Distribution
Conservation Status Map
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Global Range
North America, north to the treeline, including Newfoundland; south to the Gulf Coast, Rio Grande, and lower Colorado River valleys; introduced and now widespread in Old World.