FIELD BOOK OF MAMMALS 



hair with which is mixed much longer, hard, ghstening hairs 

 and long spines; spines stiff, sharp, and barbed, and occurring 

 all over upperparts from crown of head and sides to end of tail ; 

 underparts spineless; gait plantigrade. 



Color. — Sexes colored alike; no very marked seasonal 

 variation. 



Everywhere slaty black, or brownish black to black, liber- 

 ally sprinkled on upperparts and sides with light-tipped hairs 

 which are whitish to yellowish white; spines yellowish white 



Fig. 



98. Quills of Porcupine; lower figure greatly enlarged to 

 show barbed tip 



tipped with black; spines most conspicuous on rump and tail, 

 more or less concealed elsewhere; incisors orange-red. 



Immature like adults. 



Measurements. — Sexes of equal size. Total length, 36-40 

 inches; tail vertebrae, 6 inches; hind foot, 3.5-4 inches; weight 

 15 to a maximum of 35 or 40 pounds when excessively 

 fat. 



Geographical Distribution. — Most of forested North Am- 

 erica north of 40° and south in the Rocky Mountains 

 almost to the Mexican boundary. 



Food. — Bark, buds, and foliage of many trees, shrubs, and 

 plants; in winter principally bark and small twigs of cotton- 

 woods, willows, aspens, hemlocks, jackpines, elms, basswood, 

 etc. ; very fond of salt. 



Enemies. — Well equipped to protect itself against most 

 enemies, but said to be preyed upon by the Fisher. 



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