The prairie vole (Microtus ochrogaster) represents the ground-burrowing members of the new world voles. This vole is found in the north and central plains of the United States and in southern Canada, usually in dry places such as prairies and along fencerows and railroads. Its range has expanded eastward to West Virginia as a result of clear-cutting of forests (Jones et al., 1983). Voles are active by day or night (Johnson and Johnson, 1982). Although prairie and meadow voles usually occupy different habitats, where they coexist their population densities tend to be negatively correlated (Klatt, 1985; Krebs, 1977).

The prairie vole measures from 8.9 to 13 cm in length and has a 3.0- to 4.1-cm tail (Burt and Grossenheider, 1980). After reaching sexual maturity, voles continue to grow for several months (Johnson and Johnson, 1982). Adults weigh from 30 to 45 g (see table). Prairie voles maintain a relatively constant proportion of their body weight as fat (15 to 16 percent on a dry-weight basis) throughout the year (Fleharty et al., 1973).

The prairie vole inhabits a wide variety of prairie plant communities and moisture regimes, including riparian, short-grass, or tall-grass communities (Kaufman and Fleharty, 1974). Prairie voles prefer areas of dense vegetation, such as grass, alfalfa, or clover (Carroll and Getz, 1976); their presence in a habitat depends on suitable cover for runways (Kaufman and Fleharty, 1974). They will tolerate sparser plant cover than the meadow vole because the prairie vole usually nests in burrows at least 50 mm underground or in grass nests under logs or boards (Klatt and Getz, 1987).

Meadow voles, as other voles, are largely herbivorous, consuming primarily green succulent vegetation but also roots, bark, seeds, fungi, arthropods, and animal matter (Johnson and Johnson, 1982; Lomolino, 1984; Stalling, 1990). Voles have masticatory and digestive systems that allow them to digest fibrous grasses such as cereals (Johnson and Johnson, 1982). Diet varies by season and habitat according to plant availability, although meadow and other voles show a preference for young, tender vegetation (Johnson and Johnson, 1982; Martin, 1956). Voles can damage pastures, grasslands, crops such as hay and grain, and fruit trees (by eating bark and roots) (Johnson and Johnson, 1982).

"The Prairie Vole builds well-defined runways on and below ground. Surface runways are often well worn and bare of vegetation; sometimes they are covered with a layer of grass clippings. The abundance of these runways is a good index of the size of the Vole's local population. Unlike most voles, and in fact, most mammals, Prairie Voles appear to be monogamous: male-female breeding pairs stay together. Offspring are born hairless yet develop rapidly, acquiring a brown furry coat by day two, crawling three days later, and eating solid food by day 12. They are weaned at 2-3 weeks, and fully grown by two months."

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This species ranges throughout the prairie states of the United States and northward into the south-central provinces of Canada. It occurs in east-central Alberta, central Saskatchewan, and southern Manitoba south through northern Oklahoma and Arkansas, east to Ohio, West Virginia, Kentucky, central Tennessee, and westernmost Virginia; relictual populations occur in central Colorado, northern New Mexico, and (formerly) southwestern Louisiana and adjacent Texas (Musser and Carleton, in Wilson and Reeder 1993). The disjunct subspecies (M. o. ludovicianus), previously found in east Texas and western Louisiana, is apparently extinct.

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

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: East-central Alberta, central Saskatchewan, and southern Manitoba south through northern Oklahoma and Arkansas, east to Ohio, West Virginia, Kentucky, central Tennessee, and westernmost Virginia; relictual populations occur in central Colorado, northern New Mexico, and (formerly) southwestern Louisiana and adjacent Texas (Musser and Carleton, in Wilson and Reeder 1993).

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.

Range mass: 30 to 70 g.

Range length: 125 to 180 mm.

Sexual Dimorphism: sexes alike

Average basal metabolic rate: 0.41 W.

Length: 17 cm

Weight: 48 grams

Sexual Dimorphism: None

Length:
Range: 130-172 mm

Weight:
Range: 37-48 g

Habitat and Ecology

Systems

• Terrestrial

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.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: savanna or grassland

Other Habitat Features: agricultural

Comments: Lives in upland herbaceous fields; grasslands, old agricultural lands and thickets; places where there is suitable cover for runways. Also reported from jackpine woods. Habitats include ANDROPOGON-POA PRATENSIS meadows in Kansas, ARTEMISIA-grass in Wyoming, FESTUCA-DACTYLIS grasslands in Indiana. Floodplains of rivers serve as dispersal routes in Southwest. Railroad and highway right-of-ways may serve as corridors for dispersal throughout the range. Nests are placed in burrows, under boards or logs, and above ground in grassy clumps. May build winter nests in old anthills. In Kentucky, burrow systems were shallow (within 20 cm of surface), in areas of lush vegetation; burrows may be deeper in areas with colder climate or more friable subsoils (Davis and Kalisz, 1992, J. Mamm. 73:582-585).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

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.

Animal Foods: insects

Plant Foods: leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts

Foraging Behavior: stores or caches food

Primary Diet: herbivore (Folivore )

Comments: Diet consists almost entirely of vegetation (grasses, forbs); some insects. Underground tunnel systems frequently are used for feeding on roots.

Prairie voles are important in nutrient cycling in prairie ecosystems and as prey animals for many predator species.

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.

Known Predators:

• hawks (Accipitridae)
• owls (Strigiformes)
• shrikes (Lanius)
• red foxes (Vulpes vulpes)
• coyotes (Canis latrans)
• bobcats (Lynx rufus)
• weasels (Mustela)
• snakes (Serpentes)

Anti-predator Adaptations: cryptic

Microtus ochrogaster is prey of:
Bubo virginianus
Mustelinae
Canis latrans
Mephitinae
Geomyidae
Spermophilus
Athene cunicularia
Tyto alba
Strigiformes
Serpentes
Accipitridae
Lanius
Mustela
Lynx rufus
Vulpes vulpes
Vulpes velox
Urocyon cinereoargenteus

Based on studies in:
Canada: Manitoba (Forest)
USA: California, Cabrillo Point (Grassland)

This list may not be complete but is based on published studies.

Microtus ochrogaster preys on:
Helianthus
Agropyron
Agrostis
Stipa

Based on studies in:
Canada: Manitoba (Forest)

This list may not be complete but is based on published studies.

Three types of social groups: male-female pair, single female, and communal groups of 2-21 individuals (due primarily to increased survival of philopatric juveniles in late fall) (see Am. Midl. Nat. 128:197, J. Mamm. 74:44-58).

Periodic high densities may occur every 2-4 years (perhaps every 2 years in Oklahoma, where heavy grazing by cattle reduces grass cover and dampens multiyear cycles, Caire et al. 1989). However, some researchers believe that distinct multiannual cycles are not characteristic of this species (see Stall 1990). Average of 25 per ha; may surpass 250 per ha in peak years (Krebs et al. 1969); peaks of >600/ha (J. Mamm. 74:47) and 1060/ha have been reported (see Stall 1990).

Annual home range rarely more than 1000 sq m; averages a few hundred sq m. Lifespan generally is one year or less.

Most remain at the natal nest until death; those that do disperse leave home at about 6-8 weeks and move short distance (e.g., 28-33 m; McGuire et al. 1993). Getz (1997) found strong natal philopatry in a low-food habitat in Illinois.

Important prey species for many predators.

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.

Communication Channels: visual ; tactile ; acoustic ; chemical

Perception Channels: visual ; acoustic

Comments: Active both day and night, year-round. Peak activity probably occurs near dusk/dawn. Diurnal activity decreases in summer; nocturnal activity decreases in winter.

Average longevity is less than 1 year, but prairie voles may live up to 3 years in captivity.

Average lifespan

Status: wild: 1 years.

Range lifespan

Status: captivity: 3 (high) years.

Typical lifespan

Status: captivity: 1 (high) years.

Maximum longevity: 5.3 years (captivity) Observations: In the wild, these animals probably live less than a year (Stalling 1990). One wild born specimen was about 5.3 years old when it died in captivity (Richard Weigl 2005).

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.

Mating System: monogamous ; polygynandrous (promiscuous)

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.

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 gestation period: 21 days.

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.

Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Average birth mass: 3.02 g.

Average gestation period: 23 days.

Average number of offspring: 3.8.

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.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female)

Breeds year-round, especially spring/fall; peaks in reproduction depend on availability of moisture. Gestation lasts 20-23 days. Several litters per year; 1-7 (average 3-4) young per litter; litter size varies with season and female size and age. Both parents (and sometimes older siblings) tend neonates. Sexually mature generally by about 5-6 weeks. In Illinois, apparently mainly monogamous (Getz et al., 1993, J. Mamm. 74:44-58).

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Species: 4
Species With Barcodes: 1

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.

US Federal List: no special status

CITES: no special status

State of Michigan List: endangered

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N4 - Apparently Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Population

Population Trend

Major Threats

Comments: Destruction of grasslands for agricultural purposes has greatly reduced the extent of suitable habitat (Caire et al. 1989). On the other hand, clearing of forests has allowed increase in distribution and abundance along eastern margin of range. In Kansas, moved out of areas subjected to experimental prairie fire (Clark and Kaufman 1990).

Conservation Actions

Management Requirements: See Stall (1990) for a few references on control of voles.

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.

Negative Impacts: crop pest

Prairie voles are important parts of the prairie ecosystems in which they live. They have also been used in research for many decades.

Positive Impacts: research and education

Comments: Regarded as a pest in areas where it damages planted trees.

Comments: Includes M. o. ludovicianus, an isolated (and apparently extinct) form formerly regarded as a distinct species. Subspecies minor exhibits strong morphometric segregation from other M. ochrogaster and merits further examination of its taxonomic status (Musser and Carleton, in Wilson and Reeder 1993, 2005).

This species has been placed in (sub)genus Pitymys by some authors; however, genic data do not support the purported close affinity of M. ochrogaster with North American species of subgenus Pitymys (Moore and Janecek 1990; see also references cited by Musser and Carleton, in Wilson and Reeder 2005).