SMALLER MAMMALS OF NORTH AMERICA 



419 



In addition they eat many kinds of seeds, 

 fruit, and other vegetable matter. Where ob- 

 tainable, grasshoppers are one of their favorite 

 foods, and from this they receive their com- 

 mon name. In Colorado, from their fondness 

 for scorpions, they are sometimes called "scor- 

 pion mice." 



Vernon Bailey's observations of a grasshop- 

 per mouse he had in captivity are illuminating 

 as to their habits, and indicate that their pres- 

 ence in numbers about cultivated land must be 

 of distinct economic value. When undisturbed 

 and well fed the captive was entirely nocturnal, 

 sleeping all day and becoming very active at 

 night. While usually quiet, sometimes jumping 

 with all his force he tried furiously to escape 

 from his small prison box. His favorite food 

 consisted of crickets, grasshoppers ranking 

 next. Among other things he ate were a black 

 beetle, ladybirds, a potato beetle, spiders, bugs, 

 and dragon flies. 



In feeding he sat upright on his haunches 

 and held the insects in his front paws, eating 

 them head first. Large grasshoppers, their tails 

 resting on the ground, were held head up by a 

 paw on each shoulder. A grasshopper would 

 sometimes kick so vigorously as to tip the 

 mouse off its balance, but was never relin- 

 quished until decapitated. 



The mouse promptly killed and ate a small 

 frog placed in his box and was expert at catch- 

 ing flies. He ate many kinds of insects, in- 

 cluding a live wasp, but appeared terror- 

 stricken if a few ants were put in with him. 

 When a dozen or more crickets and grasshop- 

 pers were put into his box at the same time he 

 at once proceeded to bite off all their heads 

 before beginning to feast upon them. 



A dead white-footed mouse was dropped in 

 and "he pounced upon it like a cat, caught it 

 by the side of the head near the ear, and be- 

 gan biting it with all the ferocity of a coon 

 dog." The bones could be heard cracking and 

 after the little beast appeared satisfied that his 

 prey was really dead he ceased worrying it and 

 an examination showed that he had bitten 

 through its skull deep into the brain. After- 

 ward he tore off and ate fragments of flesh 

 from its head, neck, and shoulders. The fero- 

 cious certainty with which he seized the white- 

 footed mouse by the head and bit through its 

 skull indicated that in relation to small mam- 

 mals he, probably like all his kind, had the 

 predatory instincts and habits of the carnivores. 



One morning he ate 12 crickets and a spider 

 in seven minutes and during a single day de- 

 voured 53 insects — 2 beetles, 8 grasshoppers, 28 

 crickets, and 15 flies — and appeared ready to 

 take more. 



Oddly enough, this grasshopper mouse, so 

 fierce toward small game, never offered to bite 

 when captured or when handled freely, but con- 

 tinued throughout his captivity to have the 

 same friendly confidence in his captor. Others 

 caught in various parts of their range have 

 shown the same characteristics. 



At night, especially early in the evening, 

 grasshopper mice utter a fine shrill whistling 

 call note. This habit appears peculiar to them 



among all the mice and may be likened to that 

 of many of the large beasts of prey in utter- 

 ing their hunting call as they sally forth for 

 the night's foray. 



THE WHITE-FOOTED MOUSE (Pero- 

 myscus leucopus and its relatives) 



{For illustration, see page 428) 



Few of our smaller wild mammals are so 

 generally known as the white-footed mice. 

 Usually a little larger and proportionately 

 shorter bodied than the house mice, they may 

 at once be distinguished from them by the con- 

 trast between the delicate shades of fawn color, 

 brown, or gray of the upper parts of the body, 

 and the snowy white feet and under parts. 

 Like other members of the genus, they have 

 cheek pouches inside the mouth for gathering 

 and carrying food to their stores. 



Their exceedingly quick and graceful move- 

 ments and their beauty of form and color 

 would make them generally attractive were it 

 not for the prejudice against all their kind re- 

 sulting from the offensive ways of the house 

 mouse. 



Mice of the genus Peromyscus, to which the 

 white- footed mice belong, are peculiar to North 

 and South America and include more species 

 and geographic races than any other American 

 genus of mammals. The white-footed mice are 

 limited to North America. Readily respon- 

 sive to the influences of environment, they have 

 developed numerous species and a large num- 

 ber of geographic races. 



These are spread over most of the continent 

 from the northern limit of trees to the tropi- 

 cal shores of Yucatan. One form has the 

 distinction of living up to an altitude of from 

 15,000 to 16.000 feet on Mount Orizaba, Mex- 

 ico, where I found its tracks in the volcanic 

 ashes at the extreme limit of vegetation. This 

 is the highest record for any North American 

 mammal. 



White-footed mice are active throughout the 

 year and thrive in every variety of situation. 

 In winter from the Northern States to the 

 Arctic circle the snowshoer traversing the for- 

 est will note their lace-work patterns of tiny 

 tracks leading across the snow from log to log 

 or tree to tree. At sunrise on the southwest- 

 ern deserts their tracks made during the night 

 often form a fine network in the dust, but 

 disappear with the first breath of the morning 

 breeze. 



They not only live everywhere in the wilder- 

 ness, but are prompt to swarm about camps 

 and other habitations, where they make free 

 with the food supplies. Few frequenters of 

 forest camps in the Northern States and Can- 

 ada have failed to see the bright eyes of these 

 pretty little animals peering at them from 

 some crevice, or the mice scurrying along the 

 log wall like little squirrels. 



They are industrious workers and once in a 

 cabin quickly locate some cozy nook in a box 

 or other secluded place to construct a warm 

 nest of any soft fibrous vegetable material 



