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Smithsonian National Museum of Natural History, North American Mammals

  Rodentia · Cricetidae · Microtus richardsoni

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Microtus richardsoni

North American Water Vole

Order: Rodentia
Family: Cricetidae

Image of Microtus richardsoni
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Conservation Status: Least Concern.

North American Water Voles can swim and dive, and are always found near water, often near fast-running glacial or spring-fed streams. Captive young voles swam voluntarily when they were only 17 days old, before they were even weaned. North American Water Voles live in alpine and sub-alpine meadows, usually at elevations between about 900 and 3,200 m. They are not known to cross valleys or expanses of forest to move from one habitat to another. They use underground nests year-round, but nests are also found on the surface after snowmelt. These may have been used during the winter, or may have been built when melting snow flooded tunnels. Water Voles do not store food, but consume dry portions of herbaceous vegetation, root buds, rhizomes, and corms (starchy underground stems) in winter, and eat seeds and bulbs in summer.

Also known as:

Richardson's Water Vole, Richardson Vole, Richardson's Meadow Vole, Richardson Meadow Mouse, Water Rat, Big-footed Mouse, Giant Water Vole, Water Vole

Sexual Dimorphism:

Males are larger than females.


Average: 252 mm
Range: 234-274 mm


Range: 72-150 g males; 68-140 g females


DeKay, J.E., 1842.  Natural History of New York.  Part I: Zoology, p. 91.  Thurlow Weed, Albany, New York, 146 pp.


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Distribution of Microtus richardsoni

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