358 



BIRD-LIFE IN WESTERN CANADA 



Still, we observe that the Ptarmigan of Colorado are the 

 same as those of the Canadian Rockies, evidence that the 

 birds have undergone no change since the time when their 

 distribution was continuous. 



Camp at Ptarmigan Pass 

 Mt. Temple to the south 



111 color as well as in distribution, Ptarmigan are of ex- 

 ceptional interest. The fact that they are snowy white in 

 winter and mixed brown, gray and black in summer is com- 

 mon knowledge, but it is not generally known that their 

 plumages are even more closely adapted to seasonal condi- 

 tions than the striking change from white to brownish would 

 imply. Thus, in the spring, the females molt before the 

 males, at times acquiring their inconspicuous nesting cos- 

 tume before the male has lost a feather of his winter dress. 

 Tn winter, both sexes are white, but in summer, the female is 

 more quietly attired than the male, who retains a few white 



