Summit Outside: Getting to know voles
January 5, 2013
The vole is a small, little creature that makes tunnels and eats the bark around trees and shrubs.
They also find the roots of many plants and bulbs delectable. Therefore, vole damage can be widespread, and frustrating to homeowners with gardens and landscapers.
Voles and moles are often confused. The name is similar. Just change the “v” for an “m.” They are seldom seen, so we can mostly identify them by the damage they leave behind.
The mole is a carnivore and eats worms, grubs and adult insects, while voles are vegetarians.
Voles, moles, gophers, mice, rats and even shrews have similar characteristics in that they all will commonly use burrows with many exit holes.
Moles make two kinds of runways, one runs just beneath the surface, looking like raised ridges. The second type of runway runs deeper and unites the feeding tunnels in a network. The soil excavated from the deep tunnels appears in mounds that resemble little volcanoes.
Voles leave no mounds. The clearest signs of the presence of voles are above-ground runways that connect burrow openings. A protective layer of grass or other ground cover usually covers the runways and the maze of runways leads to multiple burrow openings that are each about 1 1/2 to 2 inches in diameter. Fresh clippings of green grass, and greenish-colored droppings about 3/16 inch long in the runways, and near the burrows are further evidence of voles.
Although voles spend some time above ground and you occasionally can see them scurrying about, they spend the majority of their time below ground in their burrow system.
So what good are voles? Every species plays an important role in nature. Like many burrowing rodents, they play beneficial roles, including dispersing nutrients throughout the top-most soil layers. Voles store seeds and other plant matter in underground chambers.
They are actually quite intriguing little creatures and are an important food source for a multitude of other animals, making them an important part of the food chain. Among the predators of voles are martens, hawks, raccoons, owls, falcons, coyotes, foxes, snakes and weasels. Even cats and dogs have been known to eat voles.
Vole bones are often found in the pellets of many species of the owl family: the short-eared owl, the northern spotted owl, the saw-whet owl, the barn owl, the great gray owl and the northern pygmy owl.
Scientists have studied vole behavior and genetics. The prairie vole is a notable animal model for monogamous, sexual fidelity as the male is usually faithful to the female and shares in the raising of pups.
Voles cause most of their damage to plants in the winter. In my last article I wrote about the subnivean tunnels that are inhabited by small creatures such as voles. The damage to landscaping after the winter may therefore not be due to the harsh winter conditions, but the little creatures under the snow gnawing away at vegetation!
A vole resembles a mouse but with a stouter body; a shorter, hairy tail; a slightly rounder head; and smaller ears and eyes. They are somewhat similar in appearance to pocket gophers. They have a compact, heavy body; short legs; a short-furred tail; small eyes; and partially hidden ears. Their long, coarse fur is blackish brown to grayish brown. When fully grown they can measure 5-8 inches long, including the tail.
There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice, but voles belong to the lemming family. They are actually rather cute!
Voles, like many of the rodent species, are very prolific. Vole populations can expand within a very short period of time as they can have five to 10 litters a year.
Gestation lasts for three weeks. Young voles reach sexual maturity and reproduce in a month.
A female vole can produce a hundred or more progeny in less than a year.
The average life span of the smaller vole species is three to six months; rarely longer than 12 months. An estimated 88 percent of voles are believed to die within the first month of life, largely due to predation.
Vole populations regularly go through cycles of low to high numbers with occasional sudden increases that can be up to several thousand per acre.
Voles can breed any time of year, but the peak breeding period is spring.
Where snow cover is present, damage to trees can extend a foot or more up the trunk.
Most damage by meadow voles occurs during the winter as they eat and multiply under the snow. They are active throughout the day and night and do not hibernate.
Evidence of excessive surface runways, following weeks of snow cover, is characteristic of excessive meadow vole populations. The presence of large numbers of voles is often only noticeable after they have destroyed a number of plants.
Voles are not commonly found in buildings, unlike mice and some other rodents.
As with all animals, natural constraints limit vole populations, but we need a healthy population of predators like martens, raccoons, owls, hawks, falcons, coyotes, foxes and snakes.
Voles are not a huge topic for the imagination, but there exist a number of children’s stories like: “The Vole Brothers,” “The Tale of Jeremy Vole,” “Verdin Vole Visits the Vet” and “Tiffin and Toffey – the Great Vole Rescue” about Will the weasel that has stolen the baby voles.
There is a species of water vole that lives mostly in Europe which is the character Ratty in the story “Wind in the Willows.” Ratty the vole is portrayed as cultured, relaxed and friendly.
Dr. Joanne Stolen is retired from teaching microbiology at Rutgers University.