Pocket gophers are medium-sized burrowing rodents, which have external fur-lined pouches located on the outside of their mouths. They use the pouches to carry food, hence the name "pocket" gopher. There are 35 species of pocket gophers in North and South America. Pocket gophers are sometimes confused with moles because of their similar burrowing activities. Moles, however, are smaller and lack cheek pouches.

Pocket gophers have yellowish-colored incisor teeth. These incisors are always exposed. Their lips actually close behind the incisors, so they can use their teeth for digging without getting soil in their mouth. Pocket gophers vary in length from 6 to 13 inches. The color of their fur ranges from sandy brown to dark chocolate brown. The color of their fur generally matches the color of the soil where they are present. As with most burrowing mammals, pocket gophers have poor eyesight, which is compensated by other well-developed senses. They have short, hairless tails which are very sensitive and used to guide them when moving backwards in a tunnel. They have large whiskers (vibrissae) which are sensitive to movement and can be used to guide their movements even in the darkest tunnels. Their forefeet are equipped with long claws.

Fan-shaped mounds left behind by Pocket Gophers.

Pocket gophers are best identified by their external cheek pouches, and by the soil mounds they leave behind as evidence of their tunneling or burrowing activities. Mounds are fan-shaped (12 to 18 inches wide and 4 to 6 inches high) and a soil plug seals the entrance. The mounds are created when the gophers move excavated soil to the surface when tunneling.

Pocket gophers use their long powerful claws and teeth for digging their burrows. As with all rodents, their incisors grow continuously and require constant gnawing or filing to keep them at a manageable length. Soil, rocks, and other items loosened by digging are moved away with their hind feet, then bushed to the surface with their chest and forefeet.

Burrow systems consist of a main tunnel from 4 to 18 inches below the surface with a number of lateral tunnels branching off from the main tunnel. Lateral tunnels end with a soil mound or only a soil plug at the surface. Burrows are about 2 to 3 1/2 inches in diameter, depending on the size of the gopher. Pocket gophers usually construct one nest and a number of food cache chambers in deeper tunnels which branch off from the main tunnel. A nest chamber also is lined with vegetation. Nest chambers and food caches have been found as deep as 5 to 6 feet below the surface.

A burrow system is typically multi-branched. During the breeding season's a male's burrow may be more linear since its sole purpose is to intercept a female's burrow. A single pocket gopher may construct as many as 200 soil mounds in a year while moving over 4 tons of soil and bringing about 2 1/4 tons of soil to the surface each year. Burrows are continually changing, with old tunnels being sealed off and new ones excavated. A single tunnel system may consist of as much as 200 yards of tunnels. Generally, the poorer the habitat the longer the tunnels must be to meet food needs. Mound-building activity usually is greatest in spring and fall. Pocket gophers are highly territorial and will vigorously defend their tunnels from intruders. There is typically one pocket gopher per tunnel system, unless the female has a litter or it is the mating season.

Pocket gophers are active all year long. When snow is present they will tunnel in the snow. Soil from below ground burrowing is pushed up under the snow. When the snow melts, the soil cast (tubes) that are left behind provide evidence of their winter burrowing activities.

Pocket gophers reach sexual maturity the following spring after they are born and have a maximum life span of about 5 years with the average being 1 to 2 years in the wild. Females generally have only one litter a year. Litters are born from March to June. In warmer climates females may have 2 or more litters. Each litter may consist of 1 to 13 young with 3 or 4 being average. Gestation is typically 18 or 19 days with 51 days being the maximum reported. The young leave their mother's burrow system in the summer and may travel above ground for a time before digging their own burrow. The pocket gopher is prey to predators, including hawks, owls, coyotes, foxes, bobcats, skunks, weasels, badgers, bullsnakes and rattlesnakes. Young gophers are particularly susceptible to predators when dispersing above ground to a new location.

Pocket gophers are herbivores eating only plant materials such as forbs, grasses, shrubs, and trees. They eat roots that are exposed by their tunneling as well as above ground vegetation they pull into the tunnel from below, and vegetation above ground near the tunnel. Many trees and shrubs are clipped just above ground, especially under snow cover. Alfalfa, dandelions, and prickly pear cactus are preferred foods for pocket gophers.

Although pocket gophers are encountered infrequently, their solitary nature reflects their disposition. Pocket gophers are very aggressive and they often have scars from fighting with other gophers. If you encounter one, it is best to leave it alone. Remember they have large teeth and strong jaws-they can deliver a painful bite. If you wish to move a pocket gopher without harming it, carefully pick it up by its tail.

NORTHERN POCKET GOPHER (Thomomys talpoides)

 Description: Color varies greatly, but in Colorado they are usually a dark rich brown or yellowish brown with a whitish chin and belly. Rounded ears, with a dark patch behind the ear that is about 3 times the size of the ear. Northern pocket gophers have smooth upper incisors with a single indistinct groove near the inner border. They have smaller bodies and proportionately smaller feet, weighing only about 2 3/4 to 4 5/8 oz. and are only 6 1/2 to 9 1/4 inches long.

The Northern Pocket Gopher seldom appears above the ground, but when it does, it rarely ventures more than 2 1/2 feet from a burrow entrance. Except when seeking a mate, it is ferocious toward its own kind. Favorite foods consist of entirely vegetation, mostly roots of broad-leafed plants, bulbs, and tubers. Garden vegetables are often eaten below the surface with only the leafy material left above ground. Sometimes the gopher will actually pull the entire plant below the surface.

PLAINS POCKET GOPHER (Geomys bursarius)

Description: They are light brown to black in color, varying with the color of the soil, and slightly lighter color on its belly. The body is thick-set and appears heaviest anteriorly, from which it gradually tapers to the tail, widening a little at the thighs. The tail is long and sparsely haired. The eyes are tiny and beadlike, and the ears are very rudimentary, represented only by a thickened ridge of skin at the base. The feet are white with long curved claws present on the front feet for digging, and the claws on the hind feet are much smaller. The upper incisors of the Plains Pocket Gopher have 2 distinct grooves on the front surface. These pocket gophers are 7 3/8 to 14 1/8 inches long and weigh 4 1/2 to 12-1/2 oz.

The mounds of the Plains Pocket Gopher are up to 1 foot high and more than 2 feet wide and always plugged. They are often in a line, with fresh mounds indicating the direction of excavation. The burrows are shallow in the summer, usually within 1 foot of the surface and deeper in the winter, when dirt is pushed up into the snow leaving the earthen cores when the snow melts.

BOTTA'S POCKET GOPHER (Thomomys bottae)

Description: The Botta's Pocket Gopher is often reddish-brown with a blackish chin and reddish belly here in Colorado. Its tail is tan to gray and essentially hairless. The ears are rounded and 1/4 to 3/8 inches long, with a similar-sized dark patch behind it. This pocket gopher is 6 5/8 to 10 3/4 inches long and weighs about 2 1/2 to 8 3/4 oz. The Botta's Pocket Gopher has smooth upper incisor with a single indistinct groove near the inner border.

 YELLOW-FACED POCKET GOPHER (Pappogeomys castanops)

Description: This pocket gopher is a yellowish-brown color with darker feet, and hairless tail.

The Yellow-faced Pocket Gopher has one distinct groove on each upper incisor. It is 8 7/8 to 12 5/8 inches long and weighs 7 1/2 to 115/8 oz.

The Yellow-faced Pocket Gopher will often make its mounds beneath bushes or cacti. Its burrows are 3 to 4 inches wide and usually deeper than the other pocket gophers found in the same area. It feeds on plant parts, including bark from tree roots, and is considered a pest in cultivated areas.

Although pocket gophers can cause significant damage on farms and ranches, they also can cause damage to lawns and gardens in urban areas. Pocket gophers sometimes damage trees by girdling or clipping stems and by pruning roots. They may, at times, destroy underground utility cables and irrigation pipes. Frequently, this damage is greatest in new subdivisions or other areas where undeveloped tracts of land dominated by weeds occur.

In retrospect, gophers are beneficial in several ways. Their burrowing activities increase soil fertility by adding organic matter in the form of plant materials and feces. Their burrowing increases soil aeration, increases water infiltration, reduces compaction, and increases the rate of soil formation by bringing up subsoil subjecting it to weatherization.

Pocket gophers are not protected by state or federal laws. When selecting a damage-control program, consider nonlethal measures, such as habitat modification or exclusion, which may be as cost effective as lethal measures and should minimize adverse environmental impacts. We offer advice on how to reduce damage caused by gophers but it is important to recognize advantages of having pocket gophers present. We know precious little about how ecosystems operate and the consequences of losing parts of those systems. It is important to maintain biodiversity, or to retain the existing plant and animals that may later benefit humans and assist in maintaining ecosystem function. Thus, we do not promote extirpation except in those cases where local economic issues make it necessary.

EXCLUSION

 HABITAT MODIFICATION

Habitat modification techniques use knowledge of pocket gopher habits and feeding behavior to reduce or eliminate damage. Most of the techniques are for farming, such as resistant crop varieties, crop rotation, and flood irrigation. Cultivated buffer strips can be used in some urban and rural areas.

Cultivating and planting a 50 foot buffer-strip of grains and/or grasses that have shallow roots, which provide little food for foraging pocket gophers may reduce damage to lawns, gardens, and plant nurseries.

REPELLENTS

No repellents have proven effective for controlling pocket gophers. Sonic or electromagnetic devices sold commercially also have not proven to be effective. A plant called gopher purge (Euphorbia lathyris) has been promoted as a means of keeping gophers out of gardens and other areas where gophers are unwanted. Although the plant is poisonous, there is no information indicating it is effective in repelling or controlling gophers. Further, it may become a problem weed, and it reportedly killed some children who ate buds from it.

TRAPPING

Trapping can be extremely effective to eliminate pocket gophers from lawns and gardens in urban and rural areas. Pocket gophers are best trapped during spring or fall when they are most active. For trapping to be the most effective the main tunnel of an active burrow system needs to be located.

Placing Traps Effectively

1. Locate the newest mound in the area.
2. Probe to locate the main runway. The best probe to use is a metal rod 3/8 or 1/2 inch in diameter that is at least 1 yard long. Examine the new mound to find the plug where the gopher has filled up the lateral tunnel. This plug will appear as a horseshoe-shaped depression not bigger that 3 inches in diameter. The main runway will be about 15-18 inches away from the mound on the same side as the depression. Now probe the soil in this area. Push the probe into the soil at repeated locations until you find a spot that the soil gives way. The sudden release of the probe may indicate you have found a runway.
3. Using a spade, dig down until you locate the runway. Remove the soil from the runway in both directions.
4. Attach a piece of wire to two traps and fasten the wire to a stake that is driven into the ground. This stake will service to anchor the traps and assist you in relocation the set. The anchor is necessary to prevent a trapped pocket gopher from pulling the trap into the burrow.
5. Set and place two traps, one in each direction. The trigger must be placed away from the excavation in the direction of the tunnel. Place the traps well into the tunnel being careful not to spring them while placing them.
6. Open burrows attract gophers and they will be caught while trying to plug the opening. This is why it is essential to place the traps as far into the tunnel as you can. This will reduce the chance the gopher will spring the trap with any soil it may be moving to plug the opening.
7. Check your traps daily. If you have not caught your gopher within 48 hours remove the traps and reset them at another fresh mound.

Traps can be purchased from hardware stores, pest supply outlets, and garden centers.

TOXICANTS

Four rodenticides are registered for pocket gopher control in Colorado:

• Strychnine (0.25 to 0.5 % active ingredient),
• Zinc phosphide (2 % active ingredient),
• Chlorophacinone (Rozol) (0.005% active ingredient), and
• Diphacinone (Eaton's Answer) (0.005% active ingredient).

Strychnine, formulated on Milo, barley or wheat, is highly toxic and potentially hazardous to all wildlife. It usually is labeled as a Restricted-Use Pesticide. In some studies, zinc phosphide has been less effective than strychnine. Diphacinone (Eaton's Answer) is blended with a water-resistant material and is formulated in bait blocks. The blocks provide long-term control because the bait remains effective after killing resident gophers so that invading gophers also are eliminated. Since chlorophacinone (Rozol) is a multiple dose anticoagulant, more bait is required to achieve adequate control. To poison pocket gophers, place the bait in their tunnel systems by hand or with a burrow builder machine. Follow label direction carefully.

Toxicants and traps can be purchased at major garden centers.

FUMIGANTS

Federally approved fumigants include aluminum phosphide and gas cartridges. Aluminum phosphide is a restricted use chemical and can only be used by certified applicators. Fumigants are usually not very effective at reducing gopher damage as toxicants or trapping, because the gases move too slowly through the burrow system. This may allow pocket gophers to seal fumigant-treated tunnels before being overcome by the gas. Fumigants are best used in damp soil because the gas will diffuse through dry soil.