Part 21

Prairie-dogs hibernate in severe weather, those living in high, snow-covered mountains or in the far north sometimes sleeping through five or six months. In many places their hibernation is irregular, and near the southern border of their range is limited to a few inclement days now and then. In Wyoming they come out the last of March or early in April, sometimes when there is a foot or two of snow on the ground and the temperature ranges far below zero. Under such conditions they run about over the snow during the middle of the day, feeding on projecting tips of vegetation or digging to the ground.

Beginning near the southern border of their range and proceeding north, the single litter of the season, containing from four to six young, are born in March, April, or May, and a month later, when scarcely larger than chipmunks, may be seen playing about the entrance mound. When danger appears the mother sends the young helter-skelter for the refuge of the burrow, and should any be slow about going in she rushes at them, driving them to cover with shrill barks of alarm. When about half-grown the young scatter and prepare burrows of their own. Sometimes as many as six to nine of these animals may be found in a single burrow, in which, no doubt, they have taken refuge, or it may be a reunion of the season’s family.

On warm sunny days, especially at a time when nights are frosty, these fat little animals will often lie flat on the bare ground about their mounds, with legs outstretched, basking in the grateful rays. As their colonies expand by the rapid increase of their numbers, many individuals wander far in search of new locations. On the mountain plateaus of northern Arizona I know of instances where they have traversed several miles of pine and fir forest to locate in an isolated mountain park, and new colonies were established as far as six miles from their nearest neighbors.

The flesh of prairie-dogs is not unpalatable, and Navajo and Pueblo Indians are extremely fond of it. The Indians take advantage of heavy rains and turn the temporary rush of water down the holes to drown out the “dogs,” and thus capture many of them.

It is inevitable that many popular misconceptions should grow up about such numerous and interesting animals as the prairie-dogs. In the West many people believe that the burrows go down to water. In reality, like many other rodents, these animals have acquired the ability by chemical action in the stomach to transform the starchy food into water. I have seen dog towns located on a few feet of soil resting on a waterless lava bed miles in extent and more than 100 feet thick, as shown by canyons cut through it, thus proving the impossibility of the prairie-dog-well legend.

Another popular belief is that the rattlesnakes and burrowing owls living in prairie-dog towns unite as a kind of happy family in the burrows of the dogs. The truth is that the owls live and breed in deserted dog holes, while the rattlesnakes visit the occupied holes to feed on the unfortunate occupants.

=THE STRIPED GROUND SQUIRREL= (=Citellus tridecemlineatus= and its subspecies)

(_For illustration, see page 538_)

Small size and a series of thirteen narrow, well-defined stripes, or lines, marking the upperparts of the striped ground squirrel serve to distinguish it from all its relatives. Its total length is about eleven inches and its form is nearly as slender as that of the weasel. Its brightly colored markings blend so well with the brown earth and plant stems in its haunts that when quiet it is difficult to distinguish. This protective coloration is of vital service to a small animal sought by all the diurnal birds of prey, as well as by coyotes, foxes, bobcats, badgers, skunks, weasels, and snakes.

The striped ground squirrel, also known as the “gopher” or “striped gopher,” is restricted to middle North America, where it is distributed from southern Michigan and northern Indiana west to Utah, and from about latitude 55 degrees in northern Alberta south nearly to the Gulf coast of Texas. It ranges from near sea level in Texas up nearly to 10,000 feet in Colorado. Within these limits the varying climatic conditions have modified it into several geographic races, all having a close general resemblance.

Like most members of the squirrel family, the striped ground squirrels are diurnal in habits and well known wherever they occur. I first learned the ways of these odd little mammals as a boy on the prairies outside the city of Chicago, and later observed them in a high mountain valley in Arizona. In both regions they had the same habits. By preference they occupy grassy prairies, old fields, and similar situations. In many areas they are serious pests, owing to their abundance and their destructiveness to grain crops, but where the land is generally cultivated, the sheltering vegetation and their shallow burrows are destroyed by the plow, thus causing a decrease in their numbers.

The lives of the striped ground squirrels are so beset with peril that they always move abroad with watchful hesitation, pausing to listen, retreating toward their burrows at the slightest suspicious sound or movement, or rising bolt upright on their hind feet and remaining motionless as a small statue until satisfied that there is nothing to fear. They call to one another with a chirping note as well as with a shrill trilling whistle, and when alarmed by the presence of some enemy their warning call notes are heard on all sides as the alarm is passed, and all are on the alert to disappear down their burrows at the slightest suspicious movement.

When they have vanished their trilling notes are often heard from the depths of their burrows; but curiosity is one of their strongest traits, and if no disturbance follows one will almost immediately pop up its head to see the cause of the alarm. Boys, taking advantage of this habit, place an open slipping noose at the end of a long string around the entrance of the burrow, and, waiting developments, lie quietly a few yards to one side. The ensuing silence is too much for the ground squirrel to endure and soon its head appears above ground, the boy pulls the string, and the victim is dragged forth with the noose about its neck.

The entrance to the burrow of these ground squirrels is about two inches in diameter. It is usually located in the midst of grass or weedy growths, and has little or no fresh earth about it. The burrow descends for several inches almost vertically and then turns almost horizontally in a sinuous and erratic course, with numerous branches and side passages leading up to the surface. Most of these side entrances are kept plugged with soft earth. Opening off the main tunnel is a large nest chamber filled with fine dry grasses and other soft vegetable matter, and also one or more large storage chambers in which the owner lays up his garnered supplies of grain or other seeds for use during inclement weather.

These squirrels hibernate throughout their range, entering their long sleep in an excessively fat condition the last of September or in October. In the North they remain in a torpid state for six months or more.

Soon after they appear in spring they mate and the single litter of the year, containing from five to thirteen young, is born the last of May or early in June. The young are in an extremely undeveloped state at birth, being blind, hairless, and with the ears scarcely showing. They develop slowly and remain with the mother until toward fall, when, nearly grown, they scatter to care for themselves.

The striped ground squirrels are among the most carnivorous of rodents. Although they devote much time to gathering grain, seeds of various kinds, and even acorns and other nuts, which may be eaten on the spot or carried in their cheek pouches to their underground storage rooms, in addition they are known to eat insects and flesh whenever occasion offers. In fact, during seasons when such insect food as grasshoppers, caterpillars, and grubs is plentiful, these ground squirrels frequently feed mainly upon it. They are known to kill and devour mice and young birds, and when confined in a cage will sometimes kill and partly devour their own kind. When caught they fight fiercely, biting and struggling to escape. In captivity they show little of the gentleness and intelligence which are such pleasing characteristics of chipmunks and true squirrels.

=THE CALIFORNIA GROUND SQUIRREL= (=Citellus beecheyi= and its relatives)

(_For illustration, see page 539_)

Owing to its habits, the California ground squirrel is known locally as the digger-, rock-, or ground-squirrel. Its prominent ears, bushy tail, color, and form give it the general appearance of a heavy-bodied gray tree squirrel, but in reality it is a true, spermophile and close kin to the marmots.

Spermophiles are nearly circumpolar in distribution, ranging through northern lands from central Europe across Bering Strait to the Great Lakes in North America. Many species exist in North America, varying greatly in form, size, and color. They occur mainly in the western part of the continent from the Arctic coast of Alaska to the southern end of the Mexican table-land. Some species are represented by enormous numbers and do great injury to cultivated crops. Among the larger and best known of the injurious species, the California ground squirrel, with its several geographic races, occupies most of the Pacific coast region from Oregon to Lower California. It has a broad vertical distribution, extending from the seashore to about 10,000 feet altitude on the western slope of the Sierra Nevada in California, and thrives under contrasting climatic conditions, as the humid northwest coast region and the most arid deserts of Lower California.

In California, where they are generally distributed and extremely numerous over great areas, these ground squirrels are most at home among the wild oats and scattered live oaks on the open slopes of the rocky foothills and thence up through the dense chaparral, scrub oaks, piñon pines, and junipers. Above this they populate many beautiful little valleys in colonies, as well as parts of the splendid open forests of pine and fir. Below they spread out from the foothills among the ranches in the great valleys. Wherever they occur they take heavy toll from the native forage plants, and in cultivated areas their devastations of crops place these spermophiles among the most serious of mammal pests.

They are omnivorous, eating insects and flesh on occasion, but feeding mainly on seeds, fruits, and many kinds of plants. The native vegetation in their haunts contains a wonderful variety of food plants, from humble weeds in the valleys to the lordly pines of the Sierra, but most attractive to these rodents are the rich food-bearers brought by the cultivators of the soil. The squirrels gather in great numbers about farms, and in feeding upon alfalfa, wheat, and other grains, grapes, peaches, apricots, almonds, prunes, pomegranates, and a variety of other crops, cause an annual loss to the farmers of California probably exceeding $20,000,000. So serious are their depredations that great sums have been spent in attempts to destroy them with poison. The Kern County Land Company, with vast holdings in the southern end of the San Joaquin Valley, in 1911 spent more than $40,000 for this purpose. This company estimated that the ground squirrels destroyed 20 per cent of the grain crop in great areas, and that twenty of them would destroy enough forage to support a cow through the year.

Ground squirrels by choice locate their burrows among slide rock, in crevices among cliffs, under boulders and roots of trees, in ditch or dry creek banks, or under stone walls, fences, or building, but in the parks of the high Sierra, as in the foothills and lowland valleys, they dig holes out in the open with conspicuous mounds at the entrances much like those of prairie-dogs.

Well-worn trails lead from one of their burrows to another and away to a distance through the wild oats in the foothills, or in the grain and forage crops of the valleys, and along these the animals travel when foraging or paying social visits. Whenever a large rock, stump, or other prominent object is convenient, they spend hours on the top sunning themselves and keeping a sharp lookout over their surroundings. From these lookout points when they suspect danger they utter a short, shrill, whistling note which may be heard at a long distance and which sends all their neighbors scurrying for shelter. They also have a lower chattering note, uttered about the burrow when resenting an intrusion or when otherwise displeased.

Ground squirrels are agile climbers on cliffs and among rocks as well as in fruit trees, live oaks, and other low trees, but I have never seen them far from the ground in large trees. When on the ground they run in a series of bounds like tree squirrels. The long, bushy tail is carried almost straight out behind when they scamper off in alarm, but at other times is curved and undulating, much as in the tree squirrels. They gather and manipulate food with their front paws, sitting upright on their haunches to eat or look about. On one occasion when I came to a foot-bridge over a broad irrigating ditch across which a number of ground squirrels were raiding an orchard, they did not hesitate to dash at full speed into the swiftly running water and swam quickly across to seek refuge in their holes on the far side.

Like other spermophiles, the California ground squirrels hibernate for months in the cold, snow-covered parts of their winter range, but remain active throughout the year in the warmer areas, where no snow falls. Throughout their range they gather stores of seeds, grain, and acorns and other nuts, carrying them in their cheek pouches to underground store-rooms for use in bad weather. In the valleys of California they lie hidden in their burrows for days at a time during cold winter rains, but are out as soon as the sun reappears. One or more litters, each containing from six to twelve young, are born from March to late in summer, according to the locality. The young leave the nest and care for themselves when about half grown.

The swarming abundance of the California ground squirrel on foothill slopes and in fertile valley bottoms equals the congregations of prairie-dogs in their most populous districts. This abundance of small animal life supports a great variety of predatory species, as coyotes, foxes, bobcats, several kinds of hawks, and the golden eagle. Owing to its predilection for ground squirrels, the golden eagle is protected by law in California, where many of them build their nests in low live oaks only a few yards from the ground.

When house rats brought the bubonic plague to San Francisco a few years ago they also carried it across the bay and passed it on to the ground squirrels living in the foothills back of Oakland. Thence the disease spread among these animals through parts of several surrounding counties. The United States Public Health Service and the local authorities in a vigorous campaign stopped the spread of this malady, but not until the potential ability of these rodents as plague-carriers had been well established. This fact and the wide distribution of the California and other ground squirrels over a large part of the continent should not be overlooked in connection with possible future outbreaks of the plague. Fortunately, investigation and field experiments on a large scale have shown that these spermophiles may be destroyed by poison over great areas at a relatively small cost.

=THE ANTELOPE CHIPMUNK= (=Ammospermophilus leucurus= and its relatives)

(_For illustration, see page 539_)

Commonly known as the antelope, or white-tailed, chipmunk, this handsome little mammal is in reality a species of spermophile, or ground squirrel. The misnomer is due, no doubt, to its small size, striped back, and sprightly ways. From the true chipmunks it may be distinguished by its heavier proportions, and from both chipmunks and all other spermophiles by its odd, upturned tail, carried closely recurved along the top of the rump. This character renders the species unmistakable at a glance and gives it an amusing air of jaunty self-confidence.

The antelope chipmunk is characteristic of the arid plains and lower mountain slopes of the Southwest from western Colorado through Utah, northern Arizona, Nevada, the southern half of California, and all of Lower California, and down the Rio Grande Valley through New Mexico to western Texas.

Within this area it occupies a wide variety of situations. It inhabits the intensely hot desert plains near sea level in Lower California, where the temperature rises to more than 125 degrees Fahrenheit in the shade and the vegetation is characterized by such picturesque forms of plant life as cactuses of many species, yuccas, fouquerias, palo verdes, ironwood, and creosote bushes; it is found also above 7,000 feet altitude on the cool plateaus and mountain slopes of Arizona and Colorado, among sage brush, greasewood, junipers, and piñon pines. It appears equally at home skipping nimbly over rocky slopes or among slide rock in arid canyons and scurrying through the brushy growth on broad sandy plains devoid of rocks.

The antelope chipmunk has the most vivacious and pleasing personality of all the numerous ground squirrels within our borders. During the many months I have camped and traveled on horseback in their haunts I have never lost interest in them. They were forever skirmishing among the bushes or dashing away down trails or over the rocks of canyon slopes, their white tails curled impudently over their backs like flags of derision at my cumbersome advance.

Their burrows are dug in a variety of places. In the open flats they enter the ground almost vertically, and often several entrances are grouped within a few yards. In some places a little mound of loose dirt is heaped up at one side of the entrance and at others there is no trace of it. Frequently, when the ground is soft, little trails lead in different directions from the entrances, and often between holes 100 yards or more apart, as though they made many social visits. The deserted burrows of other mammals are sometimes utilized to save the trouble of digging. The burrows are often under the shelter of cactuses, bushes, and great boulders or may be among crevices in the rocks.

Antelope chipmunks are extraordinarily active and continually wander far from home in search of food or in a spirit of restless inquiry. As the traveler on horseback rides slowly along he will see them racing away in front of him, sometimes climbing to the top of a bush 100 or 200 yards in advance for a better look at the wayfarer and then scuttling down and racing on again. In this way I have seen them keep ahead of me sometimes for several hundred yards instead of hiding in some hole or shelter, as they might easily do. At other times they were so unsuspicious they would permit me to pass within a few yards with slight signs of alarm. They have a chirping call, often uttered when watching from the top of a bush, and also a prolonged twittering or trilling note, diminishing toward the end.

In the higher and colder parts of their range, where snow lies long on the ground, these spermophiles hibernate for several months, but in the warmer areas they are active throughout the year. Wherever they occur they gather food and carry it to their underground store-rooms in their cheek pouches. Like most ground squirrels, they eat many kinds of seeds and fruits as well as flesh and insects when occasion offers. About cultivated lands they are sometimes abundant and destructive, digging up corn or other grain as soon as it is planted and also taking toll of the ripening grain until they become a pest. In the desert they often gather about camps to pick up the grain scattered about when the horses are fed.

It is well for them that they are prolific, having one or more litters during spring and summer, with from four to twelve in each, as they have many enemies. Snakes and weasels pursue them into their burrows, while foxes, coyotes, badgers, bobcats, and many kinds of hawks, constantly reduce their numbers.

=THE GOLDEN CHIPMUNK= (=Callospermophilus lateralis chrysodeirus= and its relatives)

(_For illustration, see page 542_)

The golden chipmunk, or calico squirrel, as it is named in Oregon, is the most richly colored of the several geographic races of a widely known species, _Callospermophilus lateralis_, abundant among the open forests of yellow pines and firs of the western ranges, including the Rocky Mountains, Cascades, and Sierra Nevada. Although commonly known as a chipmunk, this handsome animal is a ground squirrel, or spermophile, distinguished from all its kind by heavy stripes, resembling those of a chipmunk, along the sides of its back. From the chipmunks it may be distinguished at a glance by its thick-set and often almost obese proportions, which render its movements much slower and less graceful than they are with those nimble sprites. It occurs from northeastern British Columbia to New Mexico, southern California, and even in an area in the high Sierra Madre of southern Chihuahua, where an isolated representative occupies a limited range.

Their vertical distribution extends from a moderate elevation above the sea in Oregon to above 11,000 feet in southern California. They are common in the Yellowstone and other national parks, where their size, bright markings, and activities render them conspicuous.

Everywhere their habits resemble those of the various species of true chipmunks with which they associate. They live in burrows, which they dig under the shelter of logs, rocks, stumps, roots of trees, or even in open ground, as well as in the ready-made shelter of rock slides, with conies, at timberline. Their burrows at times have several entrances within a small area. Often they occupy the burrows of other animals, including pocket gophers. They excavate burrows under cabins or barns in clearings, and abandoned mining camps or old sawmill sites frequently abound with them. Nests and storage chambers are excavated off the passageways. The nests are usually made of leaves and other soft vegetable material, but in the sheep country wool, which they find in scattered tufts, is often used.

A camping party in their haunts is certain to attract them, and, as about barns, it is necessary to keep a watchful eye on them to prevent their robbing grain sacks or other supplies. When they once locate an accessible supply of grain their industry is remarkable. I have seen a dozen or more working throughout the day, making continuous hurried trips, with loaded cheek pouches, to their dens, sometimes two hundred yards away. On approach of autumn they become continually active, gathering their winter supplies.