Mammals of the Southwest Mountains and Mesas

by George Olin

Habitat: Soft loam in the open places in the high mountains. Seldom found below 8,000 feet, but up to elevations of over 13,000 feet in New Mexico.

Description: The characteristic mounds of earth built up by this group of burrowing rodents are usually the best indication of their presence. The northern pocket gopher is of medium size. Total length 6½ to 9½ inches. Tail 1¾ to 3 inches. It is usually gray in color with darker patches behind the rounded ears. Eyes and ears are small. The short tail has a bare, blunt tip. Front claws are long and curved. The entire body is well muscled and gives an impression of power. Average number of young thought to be about four. At the high elevations at which this species lives, the young are not seen until rather late in summer.

northern pocket gopher

The northern pocket gopher is one of the hardiest rodents on the North American Continent. Even so, it would not be able to survive the climate of the inhospitable regions it sometimes inhabits were it not for the fact that is spends almost all its life underground. This creature does not hibernate, but continues busily at the task of searching out food when most other subterranean dwellers are curled up fast asleep in their cozy nests. Why the gopher should continue working, while its ground squirrel cousins sleep, is hard to say. It would seem that it has the same opportunities to lay on fat for a winter’s rest. The chief reason seems to be that the bulbs and roots upon which it feeds are always available so long as the gopher keeps extending its underground workings. On the other hand, the ground squirrels, which gather their food aboveground, are cut off from this supply as soon as cold weather drives them to shelter.

The pocket gophers are much alike. There are three genera and a considerable number of species represented in the Southwest but, except for variations due to climate and terrain, their habits are similar. Burrows usually are constructed in deep loam or alluvial soils. These tunnels seem to follow an aimless pattern. Their course is marked by mounds of earth thrown out of the workings at irregular intervals. When the gopher is engaged in throwing out this excavated earth, the entrance to the tunnel is left open until the job is completed, then tightly plugged to prevent enemies from entering. The tunnels themselves are rather small in diameter, considering the size of the gopher, for if it wishes to retrace its steps and there is no gallery near at hand in which to turn around, it can run backward almost as easily as forward. There are usually numerous rooms excavated along the course of the tunnels. In one is a warm nest constructed of grass and fibers. Others are utilized for storage rooms and at least one is reserved as a toilet, thereby keeping the rest of the workings sanitary. When the ground is covered with snow the northern pocket gopher especially is quite likely to extend its activities aboveground. Here it builds its tunnels through the snow and often packs them tightly with earth brought up from below. This remains as earth casts, when the snow melts and forms a characteristic mark of its presence.

Chief foods of pocket gophers are the bulbs, tubers, and fibrous roots encountered in the course of their diggings. Whenever an especially abundant supply is found, the surplus is stored away as insurance against the time when future excavation produces nothing. Gophers also eat leaves and stems whenever available. Some plants are pulled down through the roof of the tunnel by the roots, and some are gathered near its mouth, although these trips “outside” are fraught with danger. Coyotes, foxes, and bobcats all are willing to chance an encounter with this doughty little scrapper for the sake of the tasty meal he will furnish.

Little is known of gopher family life. For the most part, they are solitary individuals, avoiding others of their kind. At breeding time, however, they may travel some distance across country to find a mate. These trips usually are carried out under cover of darkness. The young average four in number. They are born late in the spring and do not leave to make their own homes until early autumn.

Physically the gopher exhibits a striking adaptation to its way of life. The fur is thick and warm. It keeps soil particles from working into the skin at the same time it protects the wearer from the chill of his underground workings. The heavy, curved front claws are admirable digging tools. In especially hard soil, the large strong incisors are also pressed into service for this purpose. To remove the dirt from the tunnel, the gopher becomes an animal bulldozer. The front legs are employed as a blade pushing the soil, while the powerful hind legs push the body and load towards the nearest tunnel opening. The pockets from which this creature gets its common name are never used for hauling earth. They are hair-lined pouches located in each cheek and utilized for carrying food to the storerooms. There they are emptied by placing the forefeet behind them and pushing forward. Last, by virtue of its location, but certainly not least in usefulness, is the short, almost hairless tail. It is used as a tactile organ to feel out the way when the gopher runs backwards through the tunnels. In some respects, it is of more use than the eyes although the gopher uses these too, as can be attested by the quickness with which it detects any movement near the mouth of its tunnel.

The gopher’s place in Nature seems to be akin to that of the earthworm. By turning over the soil, the gopher enables it to more readily absorb water and air. At the same time, fertility is increased by the addition of buried plants and animal matter. This is indeed a fair exchange for the plants it destroys in its quest for food.