Prairie voles usually have dark brown to black hairs that are tipped with black or brownish-yellow. This makes the fur look grizzled. In spite of this, some animals may have black, yellow, albino, or spotted fur. The belly is light tan, and the tail is dark on top and light on the bottom.
Female prairie voles have three pairs of mammary glands. All members of the species can be identified using their teeth, which have some unique ridges on them. The third lower molar has no closed triangles and three transverse loops. The third upper molar has two closed triangles.
Adults are 125 to 180 mm long, with the tail adding 25 to 45 mm to this total. Hind foot length is 17 to 23 mm, ear length is 10 to 15 mm, and weights are typically between 30 and 70 grams. Males and females are about the same size and color. (Kurta, 1995; Stalling, 1990; Stalling, 1999; University of Kansas, 2000)
Prairie voles are common in prairies, ungrazed pastures, fallow fields, weedy areas, road right-of-ways, and sometimes in soybean or alfalfa fields. If meadow voles occur in the same area, prairie voles occupy the areas with shorter, drier, and more varied vegetation. (Kurta, 1995; Stalling, 1990)
Prairie voles have different mating systems depending on the season, amount of food available, and their social structure. Some male-female pairs mate only with each other while others mate with multiple partners. (Getz and Carter, 1996; Stalling, 1990; Stalling, 1999)
Prairie voles breed all the time, except when it is too cold or too hot. Most reproduction happens between May and October. The lowest levels occur in December and January when it is cold and wet.
Pregnancy lasts 21 days. A mother gives birth to litters of 3 or 4 young. How many young are in a litter depends on the mother's age and the time of year. Young are not very well developed at birth. They have no fur, and both their eyes and ears are closed.
Young grow up quickly, and can crawl by the age of 5 days. Babies eat solid foods by the age of 12 days. After they are 2 to 3 weeks of age, the mother no longer provides her babies with milk. The young probably become independent about this time. Young enter their first molt at about 24 days of age.
Females are able to breed by the time they are 30 to 40 days old. Males take longer to be ready to breed, and cannot do so until they are 35 to 45 days old. Young are full grown by 2 months of age. (Kurta, 1995; Stalling, 1990; Stalling, 1999)
Both males and females care for the young, which are born naked and helpless in a grass-lined nest. The young average 3 grams at birth. Fur appears on the young by the second day, they can crawl by 5 days, begin eating solid food at 12 days, and are weaned between 2 and 3 weeks of age. The young begin to molt into their adult pelage by 24 days and reach their adult size within 2 months of birth. (Kurta, 1995; Stalling, 1990; Stalling, 1999)
Prairie voles are active most at dawn and dusk, but show some changes in this pattern with the seasons. Daytime activity increases in the winter and decreases in summer. Prairie voles are found in three kinds of social arrangements: as a mated pair, as single females, and as small communal groups. More prairie voles live as male-female pairs during the warm months of the year and more live in small communal groups during the cold months of the year. (Getz and Carter, 1996; Stalling, 1990)
The size of individual home ranges has not been reported.
Like other voles, prairie voles probably use several methods of communication. Different squeaks and trills may be used along with scent cues. Touching is important to these animals, allowing communication between mates and the young in their nest. Different body postures may play some role in defensive interactions within the species. (Stalling, 1990)
Prairie voles are herbivorous. Food items include soft basal segments of grasses, tubers and roots, and seeds, which may be stored below ground. Insects are eaten when they are available. In winter, prairie voles sometimes eat the bark of woody vegetation. (Kurta, 1995; Kurta, 1995)
Prairie voles use an extensive runway system comprized of grass tunnels that helps to hide them from predators. Prairie voles are preyed upon by a wide variety of small to medium-sized predators. They are important as a prey base for raptors, owls, snakes, weasels, foxes, and bobcats. (Kurta, 1995; Stalling, 1990)
In places near agricultural fields or gardens, prairie voles may be considered pests. Prairie voles cause damage to trees by stem injury, with pines most commonly affected. (Lesnar, 1997; Stalling, 1999)
Prairie voles are important parts of the prairie ecosystems in which they live. They have also been used in research for many decades. (Stalling, 1999)
Loss of native prairies is causing a decline in prairie vole populations in parts of the upper Midwest. They are listed as endangered in the state of Michigan. (Lesnar, 1997)
Microtus is a greek word for "small ear" and ochrogaster is Greek for "yellow belly". Prairie voles undergo a two to four year population cycle where populations increase and decrease dramatically in that cycle. (Lesnar, 1997; Stalling, 1990)
Nancy Shefferly (editor), Animal Diversity Web.
Melissa VanderLinden (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.
Getz, L., C. Carter. 1996. Prairie vole partnerships. American Scientist, 84: 56-62.
Kurta, A. 1995. Mammals of the Great Lakes Region. Ann Arbor, Michigan: The University of Michigan Press.
Lesnar, D. 1997. "Prairie Vole (*Microtus ochrogaster*)" (On-line). Accessed 28 November 2001 at http://www.northern.edu/natsource/MAMMALS/Prairi1.htm.
Stalling, D. 1990. *Microtus ochrogaster*. Mammalian Species, 355: 1-9.
Stalling, D. 1999. Prairie vole| Microtus ochrogaster . D Wilson, S Ruff, eds. The Smithsonian Book of North American Mammals. Washington, D.C.: The Smithsonian Institution Press in Association with the American Society of Mammalogists.
University of Kansas, 2000. "*Microtus ochrogaster*" (On-line). Mammals of Kansas. Accessed 28 November 2001 at http://www.ksr.ku.edu/libres/Mammals_of_Kansas/microt-ochro.html.