Microtus ochrogasterprairie vole

Geographic Range

Prairie voles, Microtus ochrogaster, occur from northeastern New Mexico to northern Alabama, western West Virginia, and northwest to central Alberta. (Stalling, 1990)

Habitat

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)

Physical Description

Microtus ochrogaster maintains uniform coloration throughout the year. It has dark brown to black hair tipped with black or brownish-yellow. This gives a grizzled effect to most of the pelage. The ventrum is light tan. The tail is bicolored. Occasionally, color variants with yellow, black, albino or spotted fur may be found.

Prairie voles have five plantar tubercles on the hind feet and females have three pairs of mammary glands. The third lower molar has no closed triangles and three transverse loops. The third upper molar has two closed triangles.

Adults have a total length of 125 to 180 mm, tail length of 25 to 45 mm, hind foot length of 17 to 23 mm, ear length of 10 to 15 mm, and weight between 30 and 70 grams. There is no significant sexual dimorphism in size or coloration. (Kurta, 1995; Stalling, 1990; Stalling, 1999; University of Kansas, 2000)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    30 to 70 g
    1.06 to 2.47 oz
  • Range length
    125 to 180 mm
    4.92 to 7.09 in
  • Average basal metabolic rate
    0.41 W
    AnAge

Reproduction

Mating systems in prairie voles vary with season, food availability, and communal social structure. Some male-female pairs are monogamous while other males and females are likely to mate with multiple partners. (Stalling, 1990; Stalling, 1999; Getz and Carter, 1996; Stalling, 1990; Stalling, 1999)

Prairie voles breed throughout the year except during severe winters and summers. The highest levels of reproductive activity occur between May and October, and the lowest levels in December and January.

Gestation lasts 21 days, after which 3 or 4 hairless young are born. Young are altricial at birth, with both eyes and ears closed. Maternal age, size, and time of year have an effect on litter size.

Young develop rapidly. Within 5 days of birth they are able to crawl. They consume solid foods by the age of 12 days. Weaning occurs at 2 to 3 weeks. Young enter their first molt at about 24 days of age.

Females mature at 30 to 40 days and males at 35 to 45 days. Adult size is reached withing 2 months of birth. Young are independent shortly after weaning. (Kurta, 1995; Stalling, 1990; Stalling, 1999)

  • Breeding interval
    These animals can produce several litters per year. The maximum is about one litter every month and a half.
  • Breeding season
    Breeding occurs year-round.
  • Range number of offspring
    3 to 4
  • Average number of offspring
    3.8
    AnAge
  • Average gestation period
    21 days
  • Average gestation period
    23 days
    AnAge
  • Range weaning age
    2 to 3 weeks
  • Average time to independence
    3 weeks
  • Range age at sexual or reproductive maturity (female)
    30 to 45 days
  • Range age at sexual or reproductive maturity (male)
    30 to 45 days

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)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • male
      • female

Lifespan/Longevity

Average longevity is less than 1 year, but prairie voles may live up to 3 years in captivity. (Kurta, 1995; Stalling, 1990)

  • Average lifespan
    Status: wild
    1 years
  • Range lifespan
    Status: captivity
    3 (high) years
  • Typical lifespan
    Status: captivity
    1 (high) years
    AnAge

Behavior

Microtus ochrogaster is crepuscular, though activity periods shift 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. The distribution of these social arrangements in prairie vole populations varies seasonally, with a larger proportion of male-female pairs during the warm months of the year and more communal behavior in the cold months of the year. (Getz and Carter, 1996; Stalling, 1990)

Home Range

The size of individual home ranges has not been reported.

Communication and Perception

As is true of most rodents, communication is likely to involve a number of different mechanisms. Although not specifically reported for these animals, vocalizations are common in rodents, as are scent cues. Tactile communication is important between mates and within a nest containing young. Further, different body postures seem to play some role in defensive interactions within the species. (Stalling, 1990)

Food Habits

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)

  • Animal Foods
  • insects
  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • seeds, grains, and nuts

Predation

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)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Prairie voles are important in nutrient cycling in prairie ecosystems and as prey animals for many predator species. (Kurta, 1995; Stalling, 1990)

Economic Importance for Humans: Positive

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)

  • Positive Impacts
  • research and education

Economic Importance for Humans: Negative

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)

  • Negative Impacts
  • crop pest

Conservation Status

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)

Other Comments

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)

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Melissa VanderLinden (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5? N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

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.