For other uses, see Vole (disambiguation).
Not to be confused with Mole (animal).
The bank vole (Myodes glareolus) lives in woodland areas in Europe and Asia.
Arvicolinae, in part
A vole is a small rodent resembling a mouse but with a stouter body, a shorter, hairy tail, a slightly rounder head, smaller ears and eyes, and differently formed molars (high-crowned and with angular cusps instead of low-crowned and with rounded cusps). There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice in North America. Vole species form the subfamily Arvicolinae with the lemmings and the muskrats.
4 Genetics and sexual behavior,
7 External links,
Voles are small rodents that grow to 3-9 in (7.6-23 cm), depending on the species. They can have five to 10 litters per year. Gestation lasts for three weeks and the young voles reach sexual maturity in a month. As a result of this exponential growth, vole populations can grow very large within a very short period of time. Since litters average five to 10 young, a single pregnant vole can result in a hundred or more active voles in less than a year.
Voles are commonly mistaken for other small animals. Moles, gophers, mice, rats and even shrews have similar characteristics and behavioral tendencies. Since voles will commonly use burrows with many exit holes, they can be mistaken for gophers or some kind of ground squirrel.
They will readily thrive on small plants. Like shrews, they will eat dead animals and, like mice or rats, they can live on almost any nut or fruit. Additionally, voles will target plants more than most other small animals, making their presence evident. Voles will readily girdle small trees and ground cover much like a porcupine. This girdling can easily kill young plants and is not healthy for trees or other shrubs.
Voles will often eat succulent root systems and will burrow under plants or ground cover and eat away until the plant is dead. Bulbs in the ground are another favorite target for voles; their excellent burrowing and tunnelling skills give them access to sensitive areas without clear or early warning. The presence of large numbers of voles is often only identifiable after they have destroyed a number of plants. However, like other burrowing rodents, they also play beneficial roles, including dispersing nutrients throughout the upper soil layers.
Many predators, such as martens, raccoons, owls, hawks, falcons, coyotes, foxes, snakes, the red-tailed hawk, weasels, cats and dogs, eat voles. Vole bones are often found in the pellets of the short-eared owl, the northern spotted owl, the saw-whet owl, the barn owl, the great gray owl and the northern pygmy owl.
The average life of the smaller vole species is three to six months. These voles rarely live longer than 12 months. Larger species, such as the European water vole, live longer and usually die during their second, or rarely their third, winter. As many as 88% of voles are estimated to die within the first month of life.
Genetics and sexual behavior:
The prairie vole is a notable animal model for its monogamous sexual fidelity, since the male is usually faithful to the female, and shares in the raising of pups. The woodland vole is also usually monogamous. Another species from the same genus, the meadow vole, has promiscuously mating males, and scientists have changed adult male meadow voles' behavior to resemble that of prairie voles in experiments in which a single gene was introduced into the brain via a virus.
The behavior is influenced by the number of repetitions of a particular string of microsatellite DNA, and the same DNA sequence is found in humans. Male prairie voles with the longest DNA strings spend more time with their mates and pups than male prairie voles with shorter strings. However, other scientists have disputed the gene's relationship to monogamy, and cast doubt on whether the human version plays an analogous role. Physiologically, pair-bonding behavior has been shown to be connected to vasopressin, dopamine, and oxytocin levels, with the genetic influence apparently arising via the number of receptors for these substances in the brain; the pair-bonding behavior has also been shown in experiments to be strongly modifiable by administering some of these substances directly.
Voles have a number of unusual chromosomal traits. Species have been found with 17 to 64 chromosomes. In some species, males and females have different chromosome numbers, a trait unusual in mammals though it is seen in other organisms. Additionally, genetic material typically found on the Y chromosome has been found in both males and females in at least one species. In another species, the X-chromosome contains 20% of the genome. All of these variations result in very little physical aberration; most vole species are virtually indistinguishable.
Subfamily Arvicolinae (in part)
Genus Arvicola - water voles,
Genus Blanfordimys - Afghan vole and Bucharian vole,
Genus Chionomys - snow voles,
Genus Lemmiscus - sagebrush vole,
Genus Microtus - voles,
Genus Neodon - mountain voles,
Genus Proedromys - Duke of Bedford's vole,
Tribe Ellobiusini - mole voles
Genus Ellobius - mole voles,
Genus Lagurus - steppe vole (also called steppe lemming),
Genus Alticola - voles from Central Asia,
Genus Eothenomys - voles from East Asia,
Genus Hyperacrius - voles from India (True's vole), Afghanistan and Pakistan (Murree's vole),
Genus Myodes - red-backed voles,
Genus Dinaromys - voles from the Dinaric Alps,
Genus Arborimus - tree voles,
Genus Phenacomys - heather voles,