Rodents
Gopher
Pocket gophers are burrowing rodents, named "pocket" because they have furlined pouches outside of their mouth, one on each side of the face. These pockets, which are capable of being turned inside out, are used for carrying food. Pocket gophers have a short neck and are powerfully built in the forequarters. Their head is fairly small and flattened. The forepaws are large-clawed and their lips close behind their large incisors providing excellent gnawing and digging behavior. Gophers have small external ears and small eyes. As sight and sound are severely limited, gophers are highly dependent on the sense of touch.
Pocket gophers are medium-sized rodents ranging from about 5 to nearly 14 inches long (head and body). Adult males are larger than adult females. Their fur is very fine, soft, and highly variable in color. Colors range from nearly black to pale brown to almost white. In the United States there are 13 species and three genera. They thrive in looser, fairly deep, light-textured soils with good herbage production, especially when that vegetation has large, fleshy roots, bulbs, or tubers. Fields, parks and lawns make great habitats.
Pocket gophers feed on plants in three ways: 1) they feed on roots that they encounter when digging; 2) occasionally they go to the surface, venturing only a short body length or so from their tunnel opening to feed on above ground vegetation; and 3) they pull vegetation into their tunnel from below. Pocket gophers are strict herbivores, eating roots, grasses, shrubs, and trees. Their fan-shaped soil mounds and plugged tunnel entrances are characteristic evidence of their presence. Typically, there is only one gopher per burrow system. Obvious exceptions are when mating occurs and when the female is caring for her young.
Burrows are made up of a main burrow, generally 4 to 18 inches below and parallel to the ground surface, with various numbers of lateral burrows from the main one. These end at the surface with a soil mound or sometimes only a soil plug. There are also deeper branches off the main burrow that are used as nests and food caches. Larger chambers along the main tunnel are feeding and resting locations. Nest chambers have dried grasses and other grasslike plants formed into a ball. The maximum depth of some portions of a burrow may be as great as 5 or 6 feet. The diameter of a burrow is typically 3 inches. The number of soil mounds on the surface of the ground may be as large as 300 per animal in a year. A single burrow system may contain up to 200 yards of tunnels. The poorer the food habitat, the larger the burrow system required to provide sufficient sustenance for its occupant. Densities vary with reports of 16 to 20 per acre being very common. Average life span of gophers varies from just over 1 year to nearly 3 years. Average longevity appears to change inversely with population density.
Damage caused by gophers includes consumption of vegetation, destruction of underground utility cables and irrigation pipe, and smothering of surface greenery by dirt mounds. Gophers damage trees by stem girdling and clipping, root pruning, and root exposure caused by burrowing. Soil brought to the surface in mounds becomes more susceptible to erosion. Gophers are a neighborhood problem, as old tunnels will be taken over by new gophers from adjacent areas.
In irrigated areas, gopher tunnels can channel water runoff, causing loss of surface irrigation water. Gopher tunnels in ditch banks and earthen dams can weaken these structures, causing water loss by seepage and piping through a bank or the complete loss or washout of a canal bank. The presence of gophers also increases the probability of snake activity, which can also cause considerable auxiliary damage.
Life Cycle:
Pocket gophers reach sexual maturity in the spring following their birth. In the northern part of their range they have 1 litter per year. In the southern part they may have 2 litters per year. Litter sizes range from 1 to 10 but typically average 3 to 4. Average life span of gophers varies from just over 1 year to nearly 3 years.
