Pocket Gophers

Plains pocket gopher, Geomys bursarius

Pocket gophers cause substantial damage to agricultural crops, lawns, range-land, and tree plantings. Gophers feed primarily on the underground portions of plants and trees. Damage often is undetected until a tree shows above-ground signs of stress; by then damage is frequently lethal (Cummings and Marsh 1978). Pocket gophers may also damage plastic irrigation lines on agricultural lands as well as underground pipes, cables, and electric wires.

On rangeland, soil disturbance and mound building by pocket gophers result in increased plant diversity and a replacement of perennial by annual grasses (McDonough 1974, Foster and Stubbendieck 1980, Marsh 1985). They can greatly reduce the carrying capacity of rangeland for livestock. They can be a serious pest in alfalfa by feeding on the leaves, stems, and roots (Marsh 1985). Gopher mounds can cause equipment breakage and increased wear on haying machinery. Gopher tunnels result in water loss in irrigated areas (Case and Jasch 1994).

Pocket gophers are a major impediment to reforestation in the western United States (Crouch 1986). During winter pocket gophers often forage above ground by tunneling in the snow. Coniferous trees have been found debarked to a height of 12 feet (3.5 m) by pocket gophers working under the snow (Capp 1976). Gophers also fill some of the snow tunnels with soil, thus forming long tubular “casts” that remain after the snow melts.

Pocket gopher presence is easily deter-mined by fan-shaped soil mounds in contrast to the conical mounds of moles. Burrow entrances are usually plugged. Aboveground debarking injuries caused by pocket gophers show small tooth marks, differing from the distinct broader grooves left by porcupines, and the finely gnawed surface caused by meadow voles. Gophers will at times pull saplings and vegetation into the burrow.

Summary of Damage Prevention and Control Methods

Exclusion

Generally not practical.

Small mesh wire fence may provide protection for ornamental trees and shrubs or flower beds.

Plastic netting protects seedlings.

Cultural Methods

Damage resistant varieties of alfalfa. Crop rotation. Grain buffer strips. Control of tap-rooted forbs. Flood irrigation. Plant naturally resistant varieties of seedlings.

Repellents

Synthetic predator odors are all of questionable benefit.

Toxicants

Baits: Strychnine alkaloid. Zinc phosphide. Chlorophacinone. Diphacinone.

Fumigants

Carbon monoxide from engine exhaust. Others are not considered very effective, but some are used: Aluminum phosphide. Gas cartridges.

Trapping

Various specialized gopher kill traps. Common spring or pan trap (sizes No. 0 and No. 1).

Shooting

Not practical.

Other

Buried irrigation pipe or electrical cables can be protected with cylindrical pipe having an outside diameter of at least 2.9 inches (7.4 cm).

Surrounding a buried cable with 6 to 8 inches (15 to 20 cm) of coarse gravel (1 inch [2.5 cm] in diameter) may provide some protection.