Microtus pennsylvanicus
meadow vole

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).

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).

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).

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

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).

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

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).

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.

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.

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).

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

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

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