Wednesday, March 26, 2014
With the winter snows finally melting away many are often surprised to find a series of tiny trails on the surface of their lawns and turfgrass fields. These are vole highways.
Voles are often called meadow or field mice. While they are similar to a house mouse in general size and shape, they have some important differences. Voles have small eyes and ears, stocky bodies and short tails when compared to other mice, but even more important is that they very seldom invade homes. Rather, they prefer to live in grassy fields or landscape beds.
Voles are herbivores. They eat seeds as well as leaves and stems of grasses and sometimes other green vegetation and occasionally, roots and bulbs. Often voles are attracted to, and take up residence under bird feeders where the seed is scattered and litters the ground. Removing or limiting this food source will, in turn, limit the voles in that area. Some have found that moving the bird feeders to areas that are less susceptible to vole damage is the preferred approach.
Voles do not hibernate during the winter months. They are active even during the winter and when snow is on the ground. They seem perfectly happy and actually do very well under the protection of the snow cover chewing away on the turfgrass plants. When the snow retreats what is left is a series of surface runways through turf areas. These measure about 2 inches wide and sometimes many feet in length. Fortunately, although these runs are an eye-sore now, they do not significantly damage the turfgrass. With the spring growth, these paths will fill in and the voles will soon be forgotten.
Even more damaging than the trails that they make in turfgrass, however, is the potential injury they may wreak on other plants. Voles can seriously injure trees, shrubs (and sometimes plastic irrigation lines) when they gnaw on them. And gnawing is what rodents do best! Rodents, including voles, seem to gnaw on everything, either for food or for fun. If given enough time to gnaw on the base of a tree, voles may completely girdle it, which will kill even a large tree.
When controls are required it is important to remember that voles are a major food source of many vertebrates including birds of prey. Their main protection from these predators is snow or dense vegetative cover. While we have little control over snow, an effective way to manage voles is to reduce their vegetative cover. Mow tall grasses in the fall so that they do not fall over and create vole habitat during the winter. Trim trees and shrubs including low lying plantings plants such as arborvitae, yews, junipers such that they are up off the ground. When possible, use rock mulch rather than bark mulch in the flower gardens and beds because this is much less favorable to voles. Mouse snap traps, baited with peanut butter and placed in the vole run, also can be used to control small, pesky, populations. When major infestations have to be controlled immediately, rodenticides may also be effective. Extreme caution must be exercised when employing them. These are mostly formulated as baits to be placed into burrow openings. Remember that other animals (including dogs and cats) dig for and prey on voles and will become exposed to baits if not used sparingly and properly. Always consult state regulations and use all pesticides strictly in accordance with label restrictions. Happy trails !!!
Tim Gibb, Turfgrass Entomologist
Judy Loven, Vertebrate Control Specialist