Microtus pennsylvanicusmeadow vole

Geographic Range

Microtus pennsylvanicus is the most widespread vole in North America. Its east to west range is continuous from central Alaska to the Atlantic coast. South of the Canadian border, its western limit is the Rocky mountains. The meadow vole is found as far south as New Mexico and Georgia (Maser and Storm 1970).

Habitat

Microtus pennsylvanicus can be found in mainly in meadows, lowland fields, grassy marshes, and along rivers and lakes. They are also occasionally found in flooded marshes, high grasslands near water, and orchards or open woodland if grassy (Jackson 1961).

Physical Description

The total length of M. pennsylvanicus ranges from 128 to 195 mm with a tail about 40% of the body length. The dorsal surface is dark blackish brown to dark reddish brown with coarse black hairs. The ventral surface is grey or white and may be tinged with light brown. The winter pelage is duller and more grey. There is no sexual variation in size or color. The skull is moderately heavy, rather long, and slightly angular. The upper cheek tooth row is relatively long, about 7.2 mm, and the third premolar, usually a distinguishing characteristic among the voles, has an anterior complex, a posterior loop, and seven triangles in between, four lingual and three labial (Maser and Storm 1970, Jackson 1961).

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    33.0 to 65.0 g
    1.16 to 2.29 oz
  • Average mass
    43.67 g
    1.54 oz
  • Range length
    128.0 to 195.0 mm
    5.04 to 7.68 in
  • Average basal metabolic rate
    0.428 W
    AnAge

Lifespan/Longevity

Meadow voles are short-lived, rarely living for longer than one year in the wild.

Behavior

The meadow vole is active at all times of the day, but tends to be more nocturnal during the summer and diurnal during the winter. Females are territorial, and males have overlapping home ranges about three times larger than those of females. Female territories are actively defended. When more than one female occurs within a territory, one is significantly larger than the others, and it is probably a mother-daughter relationship. The mother seems to prevent these offspring from breeding although the mechanism for this is unknown. During cold winter months M. pennsylvanicus, communal nesting can occur among non-overlapping maternal families consisting of non-reproducing individuals of mixed sex and age groups. The meadow vole makes extensive runways through vegetation where they deposit feces and food refuse. They are proficient diggers and swimmers. Vocalizations are primarily used in defensive situations rather than offensive (Maser and Storm 1970, Wolf 1985).

Communication and Perception

Meadow voles have keen hearing and a good sense of smell. Vocalizations are primarily used in defensive situations.

Food Habits

Meadow voles feed mainly on the fresh grass, sedges, and herbs that are found locally within their range. They will also eat a variety of seeds and grains. From May until August they subsists on green and succulent vegetation. During the fall they switch to grains and seeds, and during the winter they have been known to feed on the bark and roots of shrubs and small trees. These voles will also eat tubers and bulbs when available. When this species overlaps the range of cranberries, meadow voles feed extensively on these fruits. They also eat other types of fruit. Meadow voles will eat flesh and are cannibalistic, especially on new born young. They do not show much storage behavior, but occasionally make small caches of tubers during the fall. Meadow voles are voracious eaters, consuming close to 60% of the body weight. When eating, these animals sit up and will stand to gnaw bark or a grain stalk (Jackson 1961).

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

Predation

Meadow voles are aggressive and will attack when cornered or captured. They take refuge from predators in their system of burrows and grass tunnels. Below is a list of some predators.

Ecosystem Roles

Especially because they are so abundant in the habitats where they are found, meadow voles have crucial ecosystem roles. Many predator species rely on voles to make up a significant portion of their diet, especially owls, small hawks and falcons. In addition, meadow voles consume large quantities of grass and recycle the nutrients held in the grass through their droppings. They also help to aerate and turn the soil through their digging activities.

Economic Importance for Humans: Positive

Microtus pennsylvanicus destroys many weeds especially weed grasses, and serves as food for some fur animals and other predators (Jackson 1961).

Economic Importance for Humans: Negative

When abundant, the meadow can be a pest. It can do considerable damage to growing grain and is also a problem in orchards and forestry plantings (Jackson 1961).

  • Negative Impacts
  • crop pest

Conservation Status

The meadow vole is very abundant and has no special status.

Other Comments

Microtus pennsylvanicus first appeared in the Late Pleistocene and is very abundant in the fossil record.

Contributors

Tim Neuburger (author), University of Michigan-Ann Arbor.

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

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

diurnal
  1. active during the day, 2. lasting for one day.
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.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

frugivore

an animal that mainly eats fruit

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

internal fertilization

fertilization takes place within the female's body

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).

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.

nocturnal

active during the night

sedentary

remains in the same area

sexual

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

solitary

lives alone

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).

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

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

Jackson, H. H. T. 1961. Mammals of Wisconsin. University of Wisconsin Press: Madison.

Maser, C. and R. M. Storm. 1970. A Key to Microtinae of the Pacific Northwest. O.S.U. Bookstores Inc.: Corvallis, Oregon.

Wolf, J. O. 1985. Behavior. In Biology of New World Microtus. R. H. Tamerin ed. The American Society of Mammalogists. Special Publication 8.

"Animal Life Histories Database" (On-line).