Description:
The meadow Vole can be distinguished from other members of its family by: 1) small eyes, 2) long, soft, dark brownish-black dorsal hair, 3) silvery to dark gray underparts, 4) scantily-haired short, bicolored tail about twice the length of the hind foot, 5) short ears concealed in long loose hair, 6) females having eight nipples (two pairs pectorally and two pairs inguinally), 7) five islands of dentine in the upper second molar, and 8) upper incisors not grooved. There is no sexual dimorphism.
Natural History:
Both prairie voles and meadow voles may use the same runways, but the latter favor damper areas with higher overhead protection. Like prairie voles, the meadow vole frequently develops runways by forcing grasses aside or by cutting the bases of stems. These runways lead from the nest and radiate into foraging areas. Cut sections of grass stems and fecal pellets may be found along the trails. The nest, woven of dry grasses, sedges, weeds and other vegetable material, is lined with fine plant fibers and placed underground in winter, but is generally placed on or above ground in summer. The meadow vole is more active at night than in the day. In late fall, winter and early spring, and on cloudy days, it is active day and night. It does not hibernate. In spring, after the protective layer of snow disappears, runways that have been established on the ground beneath the snow are clearly evident. Meadow vole populations are known to fluctuate greatly from year to year, with peak densities usually being reached every three to four year, followed by high mortality and rapid decline.
Adults may attain the following dimensions: total length 155-187 mm; tail 35-50 mm; hind foot 21-24 mm; ear 11-16 m; weight 43-75 grams.
Food of the meadow vole consists mostly of fresh grasses and sedges, but seeds and many other kinds of plants are also consumed, and rarely animal material.
The meadow vole is prolific and may have many litters a year; post-partum estrus is common. It breeds throughout the warm season of the year, from spring through fall, and occasionally in mild winters. After a gestation period of 21 days, one to eleven (usually four to nine) hairless young meadow voles are born. In five to six days, their hair begins to grow and their incisor teeth erupt. Their eyes and ears, which are closed at birth, open on the eighth day. They are weaned at approximately the twelfth day. Sexual maturity may be reached in less than a month at which time the females are capable of breeding, although this may vary from year to year. Males reach sexual maturity a week or so later. The young remain with the female until the next litter is born.