544 



THE NATIONAL GEOGRAPHIC MAGAZINE 



tlie western part of the continent from the 

 Arctic coast of Alaska to the southern end of 

 the Mexican table-land. Some species are rep- 

 resented 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 geo- 

 graphic 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 ro.ooo feet altitude 

 on the western slope of the Sierra Nevada in 

 California, and thrives under contrasting cli- 

 matic conditions, as the humid northwest coast 

 region and the most arid deserts of Lower 

 California. 



In California, where they are generally dis- 

 tributed 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, pinon 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 seri- 

 ous 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 vegeta- 

 tion 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 num- 

 bers about farms, and in feeding upon alfalfa, 

 wheat, and other grains, grapes, peaches, apri- 

 cots, 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 

 igil spent more than $40,000 for this purpose. 

 This company estimated that the ground squir- 

 rels 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 bur- 

 rows 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 sur- 

 roundings. 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 dis- 

 pleased. 



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 occa- 

 sion wdien 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. Through- 

 out 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 



