The gopher (Geomys spp.), also called a pocket gopher, is a burrowing rodent that ranges from 6- 12 inches long at maturity. It has a large head and robust upper body which are necessary for excavating burrows. Gophers are generally restricted to west central Wisconsin and are more of a problem in rural areas.

Gophers can be distinguished from moles by their brown fur and robust bodies with powerful forelegs and long claws. Unlike moles, gophers are rodents with large, chisel-like teeth which they use to excavate their tunnels. These teeth can grow up to 14 inches per year. A reversible, fur-lined, external "pocket" in their cheeks used to carry food is where the common name "pocket gopher" is derived.

Gophers rely heavily on their sense of touch, although their sense of smell is developed enough to locate food and mates. Gophers see better than moles but their sense of hearing is approximately equal.

Much of a gopher's life is spent alone underground, however there may be between 6-8 gophers per acre. The exception to their solitary existence is when they are mating and raising a brood during winter and early spring. They may live up to 12 years and are most active in spring and summer. Although they are less active during the winter, they do not hibernate.

Damage

Although similar in behavior to moles, gophers present a more serious problem. Damage is most severe in the spring and fall when gophers are active near the ground surface. Because they are vegetarian, they are capable of doing more destruction to roots, seeds, bulbs and other plant parts in landscape settings. In addition, they eat approximately 60% of their body weight per day. Gophers also favor tree bark, particularly that of stone fruits, and can girdle trees. Mounds and holes are a big problem for people and animals walking and an impediment to mowing equipment.

Gophers primarily use their teeth and huge front claws to excavate their burrows. Their tunnels are larger in diameter and deeper than those excavated by moles but are much less extensive. The mound of excavated soil at the tunnel entrance can also provide a clue as to the culprit. The entrance hole to a gopher burrow is at an angle to the ground surface. In addition, the excavated soil around the entrance is on one side of the tunnel while that of a mole is often mounded around the hole like a volcano. Pocket gophers can create up to 15 mounds per day in light soils. Gopher tunnels are usually not visible on the ground surface because of their deeper location.

Monitoring

In order to determine where the active tunnel is located, identify a fresh mound of soil. On the "unfanned" side of the mound, there will be a slight depression which indicates the location of the tunnel. Probe the soil 8-10 inches away from the tunnel entrance on the unfanned side of the mound with a sharp stick or soil probe. The probe will drop 2-3 inches when it reaches the tunnel.

 

Cultural Control

Because gopher tunnels can be as deep as 5-6 feet, it is often more difficult to exclude gophers than it is to exclude moles. Physical controls such as barriers, and trapping are useful as direct physical control measures.

Barriers such as 2 inch mesh fencing will exclude gophers from a small area. The fence must be deeply trenched into the ground to be effective. This is not likely to be practical on playgrounds or sports fields because of the considerable labor and cost involved.

Trapping is a very effective means of reducing gopher problems. You will need at least two traps. Macabee or Victor Easy Set spring traps are recommended. Instructions are include with the trap and must be followed explicitly. Box-type traps are more difficult to use. Locate one of the main burrows and excavate an area near the lateral tunnel. Place two traps, each facing in opposite directions, in the burrow. Wear gloves while doing this and take care not to contaminate the traps with human scent. Attach twine to each trap and run the twine out of the burrow and attach the opposite end to a stake. This will prevent the gopher from dragging the trap further into the burrow. Take care to cover the hole you excavated to place the traps so all light is excluded. If you don't exclude all light, the gopher will attempt to push soil toward the opening and may trip the traps without being caught. If the trap fails to catch a gopher after 2-3 days, move the trap to another location.

 

Biological Control

Although gophers are protected by their underground habit, when they surface to remove soil, they are vulnerable to predators such as dogs, cats, raccoons, weasels, foxes, badgers, coyotes, and hawks. Bull snakes and owls are the key predators of gophers in rural areas. Encouraging barn owls through the placement of barn owl boxes may attract this predator to your area.

Chemical Control

Most gopher baits are strychnine based and aren't recommended because of their effects on predators that may eat the poisoned gopher. Anticoagulants such as warfarin are registered for gopher control when buried in the tunnel. They give better long-term control than strychnine and are less toxic to non-target organisms when used properly. Because the tunnels are deep and predictable, there is a tractor-mounted device that creates an artificial burrow and dispenses zinc phosphide underground. This method is safe very effective in areas where gophers are a serious problem.

Sources

"Stopping Gophers and Moles" in Common Sense Pest Control Quarterly, v.12, no. 2, Spring 1996. 23p.