About Microtus ochrogaster (Wagner, 1842)
This species, the prairie vole, has long, coarse grayish-brown fur on its upper body and yellowish fur on its lower body. It has short ears and a short tail that is somewhat darker on the upper side. Prairie voles rarely live longer than one to two years, and their life expectancy depends on predator presence and local natural environmental factors. Prairie voles are found in grasslands across the central United States and Canada. Their range extends from the eastern Rocky Mountains in the west to West Virginia in the east, and north into the Canadian Prairies. An isolated relict subspecies, the Louisiana vole, was once found in the Western Gulf coastal grasslands of Texas and Louisiana. It was reportedly abundant in the 1900s, but is now considered extinct, meaning prairie voles are extirpated from Louisiana. Prairie voles live in dry fields covered with grasses and weeds; the largest populations are typically found in fallow fields or hay fields. They dig shallow burrows and create runways through surface vegetation. In winter, they tunnel underneath snow. These runways serve many purposes, from protecting against predators to helping them access food. Prairie voles are easily disturbed, and will quickly use their burrows if they detect nearby predators or threatening disturbances. Compared to meadow voles, prairie voles prefer to live in drier areas. Prairie voles are primarily herbivorous, feeding on grasses, roots, fruit, seeds, and bark, and they also eat some insects. They store food for later use. Their predators include coyotes, hawks, owls, foxes, and prairie rattlesnakes. Prairie voles may cause damage to garden plants and small trees. During mating season, prairie voles establish individual territories and defend them from other voles. They mark their territories with urine and other secretions. When facing competitors or enemies, they take a defensive posture by raising their forefeet, extending their head forward, and chattering their teeth. Outside of mating season, prairie voles live communally. Like other voles, prairie voles can reproduce at any time of year, but their main breeding seasons are fall and spring. Unlike other voles, prairie voles are generally monogamous. The prairie vole is a well-known animal model for studying monogamous behavior and social bonding, because male and female partners form lifelong pair bonds, huddle and groom each other, share nesting and pup-raising responsibilities, and generally show a high level of affiliative behavior. However, they are not sexually faithful. While pair-bonded females usually act aggressively towards unfamiliar males, both sexes will occasionally mate with other voles if given the opportunity. The female's gestation period lasts between 20 and 30 days. Female voles produce two to four litters per year, with each litter containing two to seven young. They give birth in a vegetation-lined nest located in a burrow or a ground depression. Litter size varies based on food availability and the age of the female. The highest number of pregnancies, with the largest number of offspring per pregnancy, occur in spring and fall. Vole pups open their eyes around eight days after birth, and become able to feed on their own at approximately two weeks old.
