520 



THE NATIONAL GEOGRAPHIC MAGAZINE 



grown, and brushy locations, mainly in the open 

 country. They are equally at home, however, 

 in the beautiful grassy open forests of oak, 

 pine, and firs which clothe the slopes of the 

 great continental mountain system of Mexico 

 and Central America. 



In general they prefer comparatively dry sit- 

 uations, if there is sufficient moisture to pro- 

 duce the needed vegetation, but some species in- 

 habit swamps and even salt and fresh water 

 marshes. Although as a rule not very numer- 

 ous, at times they are very abundant and make 

 well-worn trails through the small vegetation in 

 their haunts. They are active throughout the 

 year, and in the North, like some other mice, 

 burrow through the winter snows along the 

 surface of the ground in search of food. 



So far as man is concerned, most of the 

 harvest mice are among the least offensive of 

 mammals. There are exceptions, however, 

 and, although they rarely approach habitations 

 and as a rule take but slight toll from grain 

 fields and meadows, yet in some areas they be- 

 come so numerous as to do considerable dam- 



Their fnnd includes a great variety of seeds, 

 small fruits and succulent matter mainly from 

 wild plants of no economic value. They lay 

 up' stores of seeds in their nests and in little 

 special storage places for severe or inclement 

 weather. 



Some of the species dig burrows in the 

 ground where their nests are hidden. Most 

 of them, however, build globular nests of grass 

 and other vegetable matter several inches in 

 diameter in dense grass close to the ground, 

 or up in the midst of rank growths of weeds, 

 or even as high as eight or ten feet from the 

 ground in bushes and low trees. 



Sometimes they take possession of conve- 

 nient sites already provided, such as old wood- 

 pecker holes, cavities in fence posts, knot 

 holes, and deserted birds' nests, including the 

 nests of the cactus wren and orchard oriole, 

 which they remodel to suit themselves. Their 

 nests are lined with fine downy material such 

 as the pappus of the milkweed or the cattail 

 flag, and have from one to three small open- 

 ings usually located on the underside. In 

 these neat homes they have several litters of 

 from one to seven young each year. 



Some of their bush nests three or four feet 

 from the gronnd were found when I was hunt- 

 ing on El Mirador coffee plantation in Vera 

 Cruz. Often on approaching them, the single 

 occupant would dive headlong into the grassy 

 cover below and disappear. But sometimes 

 when disturbed they would come out and run 

 about through the tops of the bushes, leaping 

 from branch to branch with all the agility ancl 

 graceful abandon of pigmy squirrels. Several 

 times they were seen to stop and sit crosswise 

 on the branches with their tails hanging 

 straight down. When they move about among 

 the branches they sometimes coil the tail 

 around the twig as an opossum might, to give 

 them a more certain hold. 



While harvest mice may be seen at their 

 nests by day, they are mainly crepuscular and 



nocturnal, and so retiring in habits that their 

 presence may be entirely overlooked unless 

 special search is made to locate them. Where 

 found their pretty ways well repay the observer 

 who has the patience to spend a little time with 

 them. 



THE GRASSHOPPER MOUSE (Ony- 

 chomys leucogaster and its relatives) 



{For illustration, see page ^2y) 



The grasshopper mice are notable for the 

 delicate coloring and velvety quality of their 

 fur. While closely resembling some of the 

 white-footed mice, they may readily be distin- 

 guished from them by more robust form, 

 short, thick tail, and the character of the fur. 



Only two species, each with numerous geo- 

 graphic races, are known and both are peculiar 

 to North America. Characteristic animals of 

 the arid and semi-arid treeless plains, plateaus, 

 and foothills of the West, their known range 

 extends from Minnesota and Kansas west to 

 the Cascades and to the Pacific coast of south- 

 ern California, and in the North, from the 

 plains of the vSaskatchewan southward to San 

 Luis Potosi, on the tableland of Mexico. 



Some races live on the grassy plains west 

 of the Mississippi, but the majority prefer the 

 looser soil and sandy areas of the more arid 

 Great Basin and the even more desert South- 

 west, where the vegetation is characterized by 

 a scattered growth of woody plants, including 

 many species of cactuses, yuccas, agaves, sage- 

 brush, grcasewood, mesquites, acacias, and 

 other picturesque types. 



Like other small mammals of the open 

 plains, the grasshopper mice live in burrows. 

 When opportunity offers they evade the labor 

 of digging these for themselves by occupying 

 the deserted holes of mice, kangaroo rats, 

 ground squirrels, prairie clogs, badgers, and 

 other animals. In these retreats they have 

 nests of soft vegetable matter and each season 

 bring forth several litters containing from two 

 to six young. 



They are active throughout the year, but 

 nothing appears to be known as to the kind 

 and amount of stores they lay up for winter 

 use. As many live far enough north to expe- 

 rience a long period of cold, witli snow cover- 

 ing the earth, there is little doubt that they 

 exercise the same provision in ])roviding stores 

 to meet the need as do many other small mam- 

 mals. 



Many, species of mice eat insects or meat 

 and even on occasion devour one of their own 

 kind. The grasshopper mice go far beyond 

 this and are often not only as fierce flesh eat- 

 ers as real carnivores, but make their diet, at 

 least during the summer season, mainly of in- 

 sects and other small invertebrates. Their bill 

 of fare includes a miscellaneous assortment of 

 several species of mice, including their own 

 kind caught in traps, small dead birds, lizards, 

 frogs, cutworms, scorpions, mole crickets, ordi- 

 nary crickets, grasslioppers, moths, flies, and 

 beetles, including tlic "potato bug." 



