FIELD BOOK OF MAMMALS 



above, grayish brown, below, white; underparts white. 

 Total length, 14 inches; tail vertebrae, 6 inches; hind foot, 

 1.44 inches. Found in "Upper Sonoran Zone in north- 

 eastern Arizona, southeastern Utah, and probably north- 

 ward along the Green River Valley, southwestern Colorado, 

 and northj^estem New Mexico." (Goldman) 

 Pale Bushy-tailed Wood Rat. — Neotoma cinerea rupicola 

 (Allen). 

 Similar to typical cinerea, but smaller, tail shorter, and color 

 paler. Upperparts cream-buff, sprinkled moderately with 

 blackish; tail above, brownish gray, lighter at tip, below, 

 white; feet clear white; underparts pure white. Total 

 length, 14 inches; tail vertebrce, 5.8 inches; hind foot, 1.7 

 inches. Found in "Big Bad Lands region from south- 

 western South Dakota, through southeastern Wyoming 

 and western Nebraska to northeastern Colorado. Upper 

 Sonoran Zone." (Goldman) 



The Wood Rat is found only in the Western Hemisphere 

 and here its range is restricted to North and Middle America, 

 with by far the greater number of species occurring in the 

 western half of the continent. Wood Rats are easily distin- 

 guished from other rodents by their size and rat-like form, the 

 only species liable to be confused with them being the two 

 introduced Rats, — the Norway Rat and the Roof Rat. Aside 

 from important dental and cranial characters, the introduced 

 Rats differ from the Wood Rats in the details set forth in the 

 discussion on page 452. 



Over much of the western range of the genus the Wood Rat 

 is a common rodent. The round-tailed species are essentially 

 mammals of the lower life zones, found on plains, deserts, and 

 in brushy areas of the more open forests; the bushy-tailed 

 species are forest dwellers, found in the Rocky Mountains and 

 adjacent ranges and in the higher life zones. In the eastern 

 United States, the only species found as far north as New 

 York is pennsylvanica, rare and local in distribution. In the 

 southeastern states, the forms of the floridana group are found. 

 From the Great Plains westward the genus is represented by 

 many forms and nearly every peculiar environment has its 

 own distinct race. 



In many places these Rats build large conspicuous nests of 

 dead twigs, leaves, and debris of various sorts, this habit being 

 especially obvious in the deserts and arid plains. In regions 

 of cactus growth the spiny cactus lobes are placed on the nest 



392 



