FIELD BOOK OF MAMMALS 



Sometimes occurring as a melanistic phase, glossy brownish 

 black above and only slightly lighter below, some of the white 

 retained as blotches. 



Immature pelage. — Above dark blackish brown, without 

 whitish ear tufts but with conspicuous black markings on front 

 of ear; below white. 



Measurements. — Total length, 6.5 inches; tail vertebrae, 1.7 

 inches; hind foot, .88 inch; ear from notch (dry specimen), 

 .56 inch. 



Geographical Distribution. — Western North America, 



Food. — Chiefly insects, such as grasshoppers, crickets, 

 scorpions, beetles, larvae, etc., occasionally other Mice; vege- 

 tation and seeds. 



Enemies. — Owls, Weasels, Foxes, Coyotes, Wildcats, and 

 other small carnivores. Snakes. 



Species and Subspecies of the Genus Onychomys 

 Leucogaster Group 



Maximilian Grasshopper Mouse. — Onychomys leucogaster leu- 

 cogaster (Wied). 

 As described above. Found in "Southern Manitoba, eastern 

 North Dakota, northeastern South Dakota, and parts of 

 extreme western Minnesota, west to Minot and Fort Clark, 

 North Dakota. Transition Zone." (Hollister) 



Audubon Grasshopper Mouse. — Onychomys leucogaster mis- 

 soiiriensis (Audubon and Bachman). 

 Slightly smaller and paler than typical leucogaster. Upper- 

 parts dark grayish brown to rich wood-brown, depending on 

 season and state of wear; rest of pelage about as in typical 

 leucogaster. Total length, 6 inches; tail vertebrae, 1,6 

 inches; hind foot, ,8 inch. Found in "Southeastern Alberta, 

 southern Saskatchewan, northern and eastern A'lontana, 

 western North Dakota, and northeastern Wyoming. North 

 to Calgary, Alberta, and Carlton, Saskatchewan; east to 

 Glenullin, North Dakota; south up the Missouri River to 

 Bozeman, Montana, and up the branches of the Powder and 

 Little Missouri Rivers into northeastern Wyoming. Chiefly 

 arid Transition." (Hollister) 



Great Plains Grasshopper M-onse.— Onychomys leucogaster 

 arcticeps (Rhoads). 

 Paler and with more buffy than missouriensis. Upperparts 

 light wood-brown washed with pinkish cinnamon over 

 posterior dorsal region; ear tufts white, but not in marked 

 contrast to rest of pelage because of its light tone, forepart 

 of ear brownish ; tail white, with narrow median stripe above, 



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