Their are eight vole species found widely throughout various ecosystems of Colorado, in heavy ground cover of grasses, grass-like plants, and litter.
Meadow voles primarily occur from north to south central Colorado and along the South Platte River. They tend to live in or near damp marshy areas or wet meadows and riparian corridors.
Prairie voles are found in grasslands and along streams and irrigated lands in eastern Colorado.
Montane voles primarily are found in the western half of Colorado in moist meadows and valleys with thick grass or forb cover from 6,000 feet to above timberline.
Long-tailed voles are common over the mountains and high plateaus of the western half of Colorado. They are most abundant in streamside meadows in marshy to dry grassy areas.
Southern red-backed voles are found in moist and well-developed coniferous forests. They are most abundant in lodgepole pine stands, usually between 8,000 and 11,000 feet.
Western heather voles are found from 7,000 to above treeline of central Colorado. They occupy a variety of habitats but are most abundant along streams.
Mogollon voles are found in the very southern part of Colorado, in Las Animas and Montezuma Counties. They occur in ponderosa pine (Pinus ponderosa) woodland or savannah, pinon–juniper and woodlands or montane shrublands.
Sagebrush voles occupy the driest of all vole habitats in Colorado. Often found in sagebrush habitat, they occur between 5,000 and 9,000 feet in western and north central Colorado.
Voles have three to six young per litter and three to 12 litters per year. Their gestation period ranges from 20 to 23 days and they breed almost year around, although most reproduction occurs in spring, summer and fall. Females may become pregnant at three weeks of age.
ECOLOGICAL VALUE
Voles, like many small rodents, are an important food source for many predators. A variety of predators feed on voles including coyotes, foxes, bobcats, weasels, snakes and several species of owls and hawks.
NON-CHEMICAL CONTROL STEPS TO HELP YOU WITH RODENTS
Habitat Modification
High vole populations cannot become established without food and lack of predation by predators. Elimination of weed ground cover and tall grasses by frequent and close mowing, tilling, or herbicide application is the most successful and longest lasting method to reduce vole damage to orchards. This will diminish the amount of available habitat and reduce their numbers. Prunings left in orchards prevent proper mowing and provide a temporary food source, which may lead to damage by voles. Planting short grasses that do not mat or lodge, such as buffalo grass, blue grama, or dwarf fescues, will provide little protective cover and may reduce vole numbers.
Meadow voles are active during the day within their runways under thick grass and vegetation. Summer removal of vegetation (2 feet radius around fruit tree trunks) provides some protection because voles avoid exposed areas. Damage to lawns can be reduced by close mowing in the fall before snow arrives and by mowing and removing tall grassy cover near lawns. To repair damage to lawns from runway construction, rake, fertilize and water the affected area. Close mowing and weed management in grassy borders adjacent to agricultural crops will reduce the habitat for voles and should reduce damage. If suitable, plant crown vetch (a legume unpalatable to voles) in orchard and field boundaries to reduce vole populations.
Exclusion
To protect against vole damage, encircle young trees and shrubs with 1/4-inch mesh hardware cloth or 3-inch diameter Vexar™ plastic-mesh cylinders. This barrier should project 18 inches above the ground and 3 to 6 inches below the surface. Vegetable and flower beds may also be protected in this manner.
Trapping
Use mouse snap traps to remove small populations of voles from backyard lawns. Place traps perpendicular to runways with the trigger end in the runway and bait with small amounts of rolled oats or peanut butter. Set traps in the fall before most damage occurs. Trapping is not practical for controlling voles in large areas or on large populations.