Once again the Front Range is dealing with extreme vole activity.

Over the summer of 2015 vole activity was at near record high levels according to CSU. As the colder weather sets in voles are focusing on plants close to their dens. This means damage to Junipers and other woody plants is increasing.

What are voles?

Voles are small, mouse-like rodents that exist throughout Colorado. Though commonly called meadow or field mice, their short tails, stocky build, and small eyes distinguish them from true mice. Voles feed on vegetation. Because of this, voles cause problems by damaging lawns, gardens, trees, Junipers, and other plants.

Vole Facts:

Voles are small with adults weighing just an ounce or two. Their overall adult body length varies from about 3.5” to 6” Though voles may differ in size and color; most are dark brown to near black and have very short tails.

Voles, like mice, have many predators including foxes, snakes, hawks, owls, coyotes, and badgers. While Voles can live for a year or more, most fall victim to predators within a few months. Unfortunately as more predators (such as foxes) are pushed out of urban areas, vole populations have exploded. Damage to urban landscapes is at an all-time high in the Denver area.

The breeding season for voles encompasses most of the year, with peaks occurring in the spring and fall. Most voles have multiple families per year. Some voles have been shown to produce upwards of 10 litters of two to five young in one year. The normal is three to five litters a year.

According to the University of Nebraska, vole populations often are cyclic and can increase from 10 to 250 voles per acre. In North America, vole populations peak about every four years. Occasionally, high vole populations last about a year before predator populations increase. These peaks to vole populations occasionally result in severe damage to crops and landscapes. At this time it appears the Front Range of Colorado is heading into one of these peak times.

Voles do the worst and most costly damage during the winter when food supplies are low. This leads them to lawns and evergreens. The chewing at the bases of these plants (especially Junipers and other shrubs) can kill them.  However, with large populations; damage to wanted plants can continue year round.

Identifying damage:

Many voles leave characteristic surface trails in lawns and other dense vegetation. These trails consist of close to the ground/root level chewing of vegetation about one to two inches wide. Small holes can often be found at the end of the trails, these holes lead to the nests.

Voles usually damage woody plants during late fall through early spring. Voles may chew woody plants leaving girdled areas. Tiny teeth marks may be visible; the chewing marks are about an eighth of an inch wide and regular in appearance.

Vole treatments, including mouse traps, can help reduce populations, but for a heavily damaged area professional treatment can save thousands of dollars with landscape damage prevention.