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. 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.
Meadow vole
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.
Reproduction
Mating in M. pennsylvanicus is promiscuous. They breed all year round with March through November being the main breeding season. The number of young in a litter varies from two to nine with six or seven as the most common litter size. Number is correlated with the size of the female, with younger females giving birth to smaller litters. Breeding is virtually continuous and the female will mate immediately after giving birth. First mating in females occurs when they are about half grown at an age of 25 days. Males mate when they reach the age of about 45 days. Baby voles are born helpless, but grow quickly. Females care for and nurse their young in the nest until they are weaned at two weeks old. Soon after weaning the young move away, or disperse, from their mother’s home range. 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.
Food Habits
The meadow vole feeds mainly on the fresh grass, sedges, and herbs that are found locally within its range. It will also eat a variety of seeds and grains. From May until August it subsists on green and succulent vegetation. During the fall it switches to grains and seeds, and during the winter it has been known to feed on the bark and roots of shrubs and small trees. It will also eat tubers and bulbs when available. When it overlaps the range of cranberries, the meadow vole feeds extensively on these fruits. It also eats other types of fruit. The meadow vole will eat flesh and is cannibalistic especially on new born young. It does not show much storage behavior, but occasionally makes small caches of tubers during the fall. The meadow vole is a voracious eater, consuming close to 60% of its body weight. When eating, it sits up and will stand to gnaw bark or a grain stalk. In captivity they should be offered a complete diet of rodent lab blocks, and rat or mouse mix, with bits of fruit or veggies regularly. Cheerios or wheat bread are great treats, in small quantities. Do NOT feed chocolate, fried foods, salted foods, candy or junk food! They may enjoy crickets and mealworms if they are captive bred, never feed wild insects as they may carry parasites. Vitamins, like Nutri-Cal are a good addition to their diet, and added calcium during nursing and growth due to demands on their systems at those times, but take care not to overdo it. Water bottles should be used to proved constant, clean water. Ceramic or stoneware food dishes work well for keeping seeds or fresh foods off the floor, and a wire mesh hopper that allows them to eat the lab blocks through without extra waste.
