Voles in Turf

Description

Unfortunately the name ‘vole' is very close to the name ‘mole' causing some confusion and miscommunication. Voles are compact rodents with stocky bodies, short legs, and short tails. We have two species that damage turf and ornamental plants in North Carolina: pine voles, Microtus pinetorum, and meadow voles, Microtus pennsylvanicus. Pine voles have small eyes and ears that are hidden by their reddish-brown fur. A pine vole’s tail is shorter than its hind leg. The adult pine vole is about 3 inches long and weighs 1 ounce or less. The meadow vole’s eyes are not covered by fur, and its ears (partly covered by hair) are visible. The tail is longer than the hind leg. Its fur is dark brown, often silvery on the underside. The adult meadow vole ranges from 31⁄2 to 5 inches long and weighs 1 to 21⁄2 ounces.

Biology

Pine voles spend most of their life underground in burrow systems whereas meadow voles spend most of their lives aboveground, living in and feeding on grasses. Meadow voles chew well-defined, visible surface runways through turf areas about 11/2 to 2 inches wide as early as March and April. Meadow voles sometimes line their runways with soil excavated from a burrow. Whole families of meadow voles typically use portions of the same runway so that runways can become quite prominent. Voles are herbivores and feed on stems and leaves of grasses but they also consume forbes and fruits. Voles are active throughout the year. During severe winters and especailly with snow cover, voles often consume roots and girdle tree trunks to the point that shrubs may topple over. Most activity occurs at dawn and dusk. Voles typically make 15 to 20 short forays from the runway. Most people realize they have voles only from the damage. With favorable conditions, voles are perhaps the most prolific of all rodents. Voles can produce from five to ten litters per year, with an average of five young per litter. Gestation is only 21 days, and young voles are sexually mature in a month or two and may live up to two years. Fortunately, predatory birds, coyotes, foxes, snakes, skunks, and other animals usually keep vole populations in check.

Cultural Control

Methods for control and damage prevention include exclusion, cultural methods such as eliminating weeds, ground cover, and litter around crops and lawns, and soil tillage. Frightening, repellents, toxicants, fumigants, trapping, and shooting are also methods used. The methods that are effective are exclusion (on a small scale) and cultural methods such as eliminating weeds, ground cover, and litter; mowing regularly and soil tillage.

Trapping

Mouse snap traps can be used to control a small population by placing the trap perpendicular to the runway with the trigger end in the runway. A peanut butter-oatmeal mixture or apple slices make good baits. The trap should be covered by a shingle to prevent pets and birds from injury. Voles are easiest to trap in fall and late winter. Trapping is not effective in controlling large vole populations because time and labor costs are prohibitive.

Chemical Control

Zinc phosphide is the most commonly used toxicant for vole control in orchards. It is a single-dose toxicant available in pelleted and grain bait formulations. Zinc phosphide baits generally are placed by rubber-glove protected hand in runways and burrow openings. Zinc phosphide baits are potentially hazardous to ground-feeding birds, especially waterfowl. Placing bait into burrow openings may reduce this hazard. Amazingly enough, zinc phosphide is available to homeowners in the garden section of some big box stores.

The anticoagulant baits used against house mice and rats are also effective in controlling voles. Anticoagulants are slow-acting toxicants requiring from 5 to 15 days to take effect. Multiple feedings are needed for most anticoagulants to be effective. One or more anticoagulant baits are registered for controlling voles in many states, but the state regulations must be consulted prior to use.

References

For assistance with a specific problem, contact your local Cooperative Extension Center