502 



THE NATIONAL GEOGRAPHIC MAGAZINE 



steadily both animals could be drawn forth and 

 the enraged owner of the burrow dispatched. 

 In this manner I have known an Indian to 

 catch more than a dozen gophers in a few 

 hours. 



Pocket gophers are active throughout the 

 winter even in the coldest parts of their range, 

 but in many places must rely largely on food 

 accumulated in their storage chambers. 



Alelting snow in the mountains and in the 

 North reveals the remains of many tunnels 

 made through it along the surface of^ the 

 ground. These snow tunnels are often filled 

 for long distances with loose earth brought up 

 from underground, and after tlie snow disap- 

 pears in spring the curious branching earth 

 forms left, winding snakelike through the 

 meadows, are a great puzzle to those who do 

 not know their origin. 



In a state of nature pocket gophers are con- 

 stantly bringing the subsoil to the surface and 

 burying humus. Over an enormous area they 

 exist in such countless thousands that their 

 work, like that of angleworms, is often of the 

 most beneficial character. On bare slopes, 

 however, their work is highly injurious, as it 

 greatly increases erosion of the fertile surface 

 soil and thus has its direct influence in chang- 

 ing world contours 



When civilized man arrives in their haunts 

 and upsets natural conditions with cultivated 

 crops the new food supply stimulates an in- 

 crease in the gopher population and their ac- 

 tivities immediately become excessively de- 

 structive and necessitate unremitting warfare 

 against them. 



THE KANGAROO RATS (Dipodomys 

 spectabilis and its relatives) 



{For illustration, see page 518) 



The desert regions of western North Amer- 

 ica have developed several peculiar types of 

 mammals, and among them are none hand- 

 somer or more interesting than the kangaroo 

 rats. These rodents, despite their name, are 

 neither kangaroos nor rats, but are near rela- 

 tives of the pocket mice, which share their 

 desert haunts. 



All are characterized by a kangaroo - like 

 form, including small fore legs and feet, long 

 hind legs and feet for jumping, and a tail 

 longer than the body to serve as a balance. 

 In addition, they have large, prominent eyes and 

 are provided with skin pouches on each side 

 of the mouth for use in holding food to be 

 carried to their store chambers. 



The color pattern, like the form, of the kan- 

 garoo rats is practically uniform throughout 

 the group. Both are well shown in the accom- 

 panying plate of Dipodomys spectabilis, the 

 largest and most strongly marked species. Its 

 total length is from 12 to 14 inches; most of 

 the other species are much smaller. 



Kangaroo rats of many species are distrib- 

 uted over most of the arid and semiarid re- 

 gions of the United States and Mexico, from 

 Nebraska, Oklahoma, and the Gulf Coast of 



Texas west to the Pacific coast, and from Mon- 

 tana and Washington southward to the Valley 

 of Mexico and throughout Lower California. 

 They are especially numerous in the southwest- 

 ern deserts, where they are the oddest and most 

 picturesque of animals. 



Although they have no near relatives in the 

 Old World, some of the African and Asiatic 

 jerboas are externally almost perfect replicas 

 of the kangaroo rats in every detail of form, 

 color, and color pattern, even to the tail mark- 

 ings. This extraordinary likeness in appear- 

 ance of two widely separated and unrelated 

 animals is made doubly significant by the fact 

 that both live in deserts and have similar 

 habits. 



Peculiarly desert animals, kangaroo rats live 

 like the pocket mice, without drinking, but ob- 

 tain the necessary water through their digestive 

 processes. They are most numerous in sandy 

 areas, and there the earth is sometimes so rid- 

 dled by their burrows as to render horseback 

 riding difficult. 



Kangaroo rats are nocturnal and always live 

 in burrows dug by themselves. As a rule they 

 prefer soft or sandy ground, but some species 

 occupy areas where the earth is hard and rocky. 

 The burrows of some species have only one or 

 two entrances with a small amount of earth 

 thrown out, but others make little mounds with 

 several openings, entering usually nearly on a 

 level or at a slight incline. These openings 

 are nearly always conspicuous, and while fre- 

 quently near bushes, no effort appears ever to 

 be made to conceal them, and a little trail often 

 leads away through the soft earth. 



The large Dipodomys spectabilis, which lives 

 mainly in New Mexico and Arizona, constructs 

 the most notable of all the dwelling places of 

 these animals. From its underground workings 

 it throws up large mounds of earth, which 

 gradually increase in size with the length of 

 time they are occupied until they are some- 

 times more than 3 feet high and 15 feet or 

 more in diameter. From three to a dozen bur- 

 ows enter these mounds, usually at the surface 

 level of the ground, but some are on the slopes 

 of the mound. The mounds, usually located in 

 open ground, with their round entrance holes 

 from four to five inches in diameter, are ex- 

 tremely conspicuous. 



Although generally scattered at varying dis- 

 ances from one another, the mounds are some- 

 times grouped in colonies. Well-worn trails 

 three or four inches broad lead awa}' from the 

 entrances, some to other mounds showing 

 neighborly intercourse and others far away to 

 the feeding grounds, sometimes 200 or 300 

 yards distant. One of the openings at the side 

 of the mound is usually the main entrance, and 

 by, day this is ordinarily kept stopped with 

 fresh earth. Within the mound and farther 

 under ground are dug a series of ramifying 

 passages, among which are located roomy nest 

 chambers and store-rooms for food. 



Kangaroo rats are not known to hibernate 

 in any part of their range. They lay up food 

 for temporary purposes at least and do not go 

 abroad in stormv or cold weather. The u'lrth- 



