FIELD BOOK OF MAMMALS 



tree trunks from choice. When feeding it often chmbs shrubs 

 for fruit or nuts. 



It is active much of the year and even in the cold parts of 

 its range may sometimes be seen on bright sunny days in 

 winter. Hibernation does not seem to be as complete as with 

 the Eastern Chipmunk. In its southern range it is above 

 ground every day in the year. 



The Chipmunk assumes two, sometimes three, very dis- 

 tinct pelages in the course of the 3^ear. The brightest pelage 

 is that of the breeding season which appears (depending upon 

 the locality where the species lives), in April, May, or June. 

 This coat is followed by the post-breeding or summer pelage 

 which usually lacks some of the intensity of the late spring or 

 early summer coat. Finally, in October or November, appears 

 the winter pelage, generally the most subdued of the annual 

 color patterns. The winter pelage is very worn and ragged in 

 appearance before it is replaced by the new fur of the breeding 

 season. Not infrequently there is enough difference between 

 the worn winter and the fresh breeding pelages to make the 

 same animal look like two distinct forms. Most of the de- 

 scriptions given in this account are those of summer pelages, 

 unless otherwise specified, but lack of space does not allow the 

 listing in detail of these different patterns for so many sub- 

 species. 



Chipmunks have only one litter of 3^oung a year, as nearly 

 as I can gather from personal observation and records, and if 

 there is any significance in the assumption of a distinct breed- 

 ing pelage we should expect no more than one litter annually. 

 While conditions are such that no more than a single litter 

 could be raised in a northern summer, there is no hindrance to 

 prevent the successful raising of more than one litter in the 

 Cliipmunks' southern range where other rodents have several 

 litters annually. The average number of young in a litter 

 is four to six. 



Chipmunks are subject to various parasites and I have 

 found them infested with ticks, the larvae of the bot-fly, and 

 internally with the threadworm. 



Genus Tamias 



Dentition: Incisors, J; Canines, 2; Premolars, \; Molars -| = 20, 

 240 



