EVOLUTION OF THE COLOKS OF BIRDS. 257 



Having now considered all the factors, which seem to 

 have an influence upon the evolution of the colors of 

 North American birds, a brief application of these prin- 

 ciples to the various families and genera must next be 

 attempted. 



ORDER GALLING. THE GALLINACEOUS 



BIRDS. 



FAMILY TETRAONIDyE. The Grouse, Partridges 



AND Quail. 



The colors of the North American representatives of 

 this family are in general protective in their nature, al- 

 though sexual characters are present in certain genera, 

 while some form of recognition marking is almost al- 

 ways found. Black and white are found in every genus, 

 while brown and gray are the principal colors of the 

 group. Red and yellow in an impure form, as reddish 

 brown and ochraceous, occur in nearly all genera, and 

 blue in combination with black or gray in two of them. 

 There are no genera in which bright colors occur. 



Genus Colinus. The Bobwhites. 



(8)* Adult male more conspicuously colored than 

 female; young w^th peculiar first plumage. 



Colors — Black, white, brown, rufous, ochraceous. 



The colors are in the main protective, the black and 

 white markings of the head being characteristic of the 

 group, and probably directive recognition marks. They 

 may very probably be for sexual recognition also, the 

 colors of the female being much less distinctly indicated, 

 the black being replaced by brown, and the white by 

 buff. 



Several forms, mostly races ; the colors due largely if not 



*These numbers refer to the table on p. 214. 

 17 



