HOLARCTIC REGION 



In the far north, on the tundra, the birds of the New World and the Old World are 

 much the same, especially the shore birds, ducks, gulls, and auks. In the northern 

 forests, too, the same or closely related species are found in Siberia and Canada: three- 

 toed woodpeckers, grouse, goshawks, ravens, jays, pine grosbeaks, and others. Farther 

 south on each continent we get admi.xtiu'es uf birds derived from groups with more 

 southern headquarters: in North America, such groups as hummingbirds, tyrant fly- 

 catchers, and American orioles; in the Old World, rollers, hoopoes, and bee eaters. 



The differences between the birds of North America and those of Eurasia have 

 caused some students to divide the area into two separate regions: Nearctic 

 Region for North America (see pp. 20-50) and Palearctic for the Eurasian area 

 (see pp. 51-58). 



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