POLYCHROMATISM 



57 



particularly where farms have been abandoned and are reverting, are found some of the 

 finest grouse coverts in the State. Similar conditions exist in many sections east of the Hud- 

 son Valley, and highly productive coverts also occur about the periphery of the Adirondack 

 forest area. 



On the other hand in the more intensively farmed valley areas, grouse populations 

 are usually low and often quite scattered. Illustrative of this are the lower Hudson Valley 

 and the lowlands of the Mohawk, Susquehanna, Chemung, and Genesee rivers. Largely due to 

 a lack of conifers, these birds are very scarce over the Ontario lake plain except in various 

 swamps of which Bergen, in Genesee County, is an example. Likewise, in the extensive forests 

 of the Adirondacks and certain portions of the Catskills, the species, although generally dis- 

 tributed, is seldom numerous. And in areas of heavy occupation by man. such as much of 

 Westchester County and Long Island, it occurs in only moderate numbers. 



POLYCHROMATISM 



Throughout all subspecies of the ruffed grouse, the occurrence of dichromatism is an out- 

 standing characteristic. Just as gray as well as black squirrels are found in the same litter, 

 and red as well as gray screech owls in the same nesl. so also do gray phase and red phase 

 grouse occur in the same brood. The differences are not apparent, however, until the bird 

 acquires adult plumage, since it is the tail and ruff feathers which are most affected. 



The most conspicuous feature is the tail which, on the one hand, may display a bright 

 rufous color, on the other, a clear gray. Furthermore the subterminal band, although almost 

 invariably black in gray-tailed birds, may in red-phase individuals, vary from black to a rich 

 chocolate. Likewise the ruffs, while usuallv black, are sotnetimes chocolate in red birds. 



C. W. Atdoitt 



PARTIAL ALBINO Rl'FFED C.ROUSL TAKEN NEAR FORT KENT. ME. 



