vole
vole, any of numerous species of small-bodied mouselike rodents of the Northern Hemisphere that are classified, along with lemmings, in the subfamily Arvicolinae of the family Cricetidae. The number of vole species, however, varies by classification, with some taxonomies identifying roughly 70 species and others listing well over 100. Voles have a blunt rather than a tapered muzzle, a tail shorter than the body, and small eyes and ears.
Voles live in a wide variety of habitats at elevations ranging from sea level to high mountains. In North America they range from Alaska southward to the mountains of Mexico and Guatemala. In Eurasia they can be found in the British Isles and across Europe and Asia to southern China, Taiwan, and Japan. The only African voles exist as an isolated population in coastal Libya. Habitats exploited by voles include prairies, steppes, semideserts, alpine and subalpine meadows, treeless tundra, and several types of forest, including cloud, deciduous, and coniferous.
The woodland vole (Microtus pinetorum) of the eastern United States is one of the smallest, weighing less than 35 grams (1 ounce) and having a body length up to 10 cm (4 inches) and a tail shorter than 3 cm (1 inch). The European water vole (Arvicola amphibius) is the largest of the native Eurasian voles, weighing up to 250 grams (9 ounces) and having a body up to 22 cm (9 inches) long and a tail up to 13 cm (5 inches). Depending upon the species, voles’ soft dense fur is generally solid gray, brown, chestnut, or reddish on the upperparts, or reddish brown on the back and gray on the sides. Underparts are paler, ranging from white to gray to brown.
The meadow vole (M. pennsylvanicus), also known as the meadow mouse, is one of the most common mammals in North America. Its geographic range is vast, extending through almost all of Alaska and Canada southward through most of the continental United States. Isolated populations are also found in Mexico. The meadow vole weighs less than 50 grams (2 ounces), and adults grow to roughly 15 to 20 cm (6 to 8 inches) in length, including the short tail (3 to 6 cm [1 to 2.4 inches]). Meadow voles have dense soft fur that is typically chestnut-brown above and gray or grayish buff on the underparts, with some individuals being much darker.
Voles are active year-round. Some species are nocturnal, some are diurnal, and others are active day and night. Their diet consists of plants and occasionally insects and fungi. Some species in some regions can be agricultural pests. Nearly all voles are terrestrial, traveling through tunnels in grass or beneath snow or via elaborate subsurface burrows. There are, however, some dramatic exceptions. Arboreal red and Sonoma tree voles (Arborimus longicaudus and A. pomo, respectively) are found only in humid coastal old-growth forests of northern California and Oregon, where they live and nest in the tops of Douglas fir, grand fir, and Sitka spruce trees and eat the outer parts of conifer needles (particularly Douglas fir).
In mountain meadows of the western United States and Canada, the semiaquatic American water voles (M. richardsoni) dwell close to clear spring-fed or glacial streams and the edges of ponds. They are adept swimmers and divers whose pathways extend along and cross over springs and streams. Their burrow entrances may be at water level or submerged. Their diet consists of roots, rhizomes, and preformed buds of perennials.
Mole voles (genus Ellobius) have tiny eyes and ears and the velvety fur common to burrowing rodents. Mole voles live in deep moist soil of the steppes and dry grasslands of Central Asia, digging elaborate burrows up to 50 cm (nearly 20 inches) below ground and eating the underground parts of plants.