THE ANIMAL AND ITS ENVIRONMENT 



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wolf. Many of these animals, including the arctic fox, the arctic 

 hare, the ptarmigan, and the collared lemming, are adapted to the 

 climatic rhythm of their environment by changing in color from 

 white in winter, when the entire landscape is snow-covered, to a 

 darker color during the summer. On the tundra nest vast numbers 

 of migratory birds, some of which, like the golden plover, fly to 

 winter homes in South America. 



Fig. 380. — Distribution of major bio tic regions in Nortii America. 



2. The Coniferous Forest Formation (Spruce-Moose Biome). — 



South of the Arctic tundra and below the high mountain tundra 

 along the Rockies and the Sierras is the great coniferous forest 

 whose dominant vegetation is evergreen, composed chiefly of spruces, 

 firs, and pines of many species. The moose and the woodland caribou 

 are characteristic animals over the greater part of the area. They 

 feed upon grass and shrubs, chiefly in open areas near streams or 

 lakes. The principal carnivore is the timber wolf, The Canada 



