?34 



MAMMALS OF AMERICA 



brown above, yellowish-red on sides, and below clear 

 white ; hair on body long, lax and remarkably soft. 

 Nocturnal in habit. 



Dental Formula. — Incisors, ~ ; Canines, -^^^ Pre- 

 molars, ^; Molars, g=i6. 



Pelage. — Adults : Sexes identical. A seasonal 

 variation, but not very conspicuous. Above, grayish- 

 brown, darker along dorsal region, becoming yellowish- 

 red on sides, and graduating into a line of fulvous; 

 underparts, feet and outside of fore legs \vh!te ; tail 

 blackish-brown above, underside and terminal eighth, 

 white. Youxg: Mouse gray above, below white. 



Measurements. — Total length. 6 inches ; tail verte- 

 brae. I." inches; hind foot. .9 inch. 



Range. — Dakota, Missouri, Nebraska, Kansas, Okla- 

 homa. Indian Territory and Texas. 



Food. — Largely insects, grasshoppers, scorpions, 

 crickets, beetles and occasionally other Mice, as well as 

 some seeds and vegetation. 



Rel.'vted Species 

 Grasshopper Mouse, or Scorpion Mouse. — Ony- 



choinys Icucoiiastcr h-uciniiislcy (Wied). Typical 

 animal as described above. Plains of Dakota, Missouri, 

 Nebraska. Kansas. Oklahoma and Texas. 



Gray Scorpion Mouse. — Onychomys Icucogaster 

 juscoiiriscus Anthony. Similar to Icucofjastcr, but 

 coloration richer and colors more contrasting. Oregon 

 and Washington. 



California Scorpion Mouse. — Onychoinys rainona 

 Rhnads. Smaller than the above species, coloration 

 brighter, more red. Soutliwestern California. 



Long-tailed Grasshopper Mouse. — Onychoinys 

 lon(/icaudus Merriam. Above, cinnamon fawn with 

 black-tipped hairs; tail about 2.15 inches. Utah. 



Yuma Grasshopper Mouse. — Onychomys torridus 

 t^crl^allidiis Mearns. Size large; coloration very pale. 

 .■\rizona and California in southern desert region. 



Dusky Grasshopper Mouse. — Onychomys fuligi- 

 nosiis Merriam, Size rather large ; ears large ; pelage 

 somewhat coarser than in the other species ; blackish- 

 slate above. Northeastern Arizona. 



The Grasshopper, or Scorpion, Mice are a well 

 characterized group related to the White-footed 

 or Deer Mice, but are easily distinguished from 

 the other Mice by their coloration, when taken 

 in connection with their short thick tail and 

 heavy body. They are probably the least de- 

 pendent upon a vegetarian diet of any of our 

 Mice and are also adapted for burrowing as is 

 shown by the long claws on the fore feet. There 

 are some fifteen species and subspecies ranging 

 in the United States. These forms are strictly 

 plain or desert type;;. 



Grasshopper Mice are nocturnal. They espe- 

 cially frequent sandy areas, and are often taken 

 in traps set at the burrows of Kangaroo Rats, 

 Ground Squirrels, and Pocket Mice. Their car- 

 nivorous pro])ensity is one of the chief obstacles 

 the collector meets in trapping the rarer desert 

 Mice, and often after nights of trapping without 

 success he is chagrined to find in one of his traps 

 the partly devoured and mangled remains of a 

 rare Pocket Mouse. Sometimes in regions where 

 Gra.sshopper Mice are plentiful, a miscellaneous 

 catch of other species will be ahuost ruined by 

 them. Much of the food of Grasshopper Mice 

 consists of soft-bodied insects, such as grass- 

 hoppers and crickets. The name Scorjiion Mice, 

 sometimes applied to these rodents, is due to a 



marked fondness for scor]5ions, which probably 

 form part of their food in Colorado, particu- 

 larly in the Southwest. Vegetable food is also 

 eaten. 



In some one of its varied forms, the Grass- 

 hopper Mouse is found from the Dakotas south 

 to Texas. They vary considerably as regards 

 their haunts. The pale form prefers a sandy 

 soil with a good growth of sagebrush. Mr. Ver- 

 non Bailey (" Biological Survey of Texas,") 

 says : " They make few holes, though two were 

 taken at the mouths of small burrows. They are 

 strictly nocturnal, and, while never seen by day- 

 light, their long-drawn fine whistle is often heard 

 in the grass between dusk and early dawn. The 

 morning round of a line of traps usually reveals 

 one or more specimens that have been attracted 

 by the oatmeal liait." Another Texan form, 

 large and dull-colored, inhabits grassy, brushy 

 land in the half-o])en cactus and mesquite coun- 

 try, and is found in the woods as well as in the 

 open. It also is strictly nocturnal, and its shrill 

 whistle has been heard not far from camp fires. 

 The Dusky Mouse of the Painted Desert and 

 the high mesas, northeastern Arizona, is a re- 

 markable example of color adaptation to environ- 

 ment, its slate-black hue according perfectly with 

 the black lava beds in which it has its home. 



