CLASS AVES (BIRDS). 



335 



verge of extinction. The numerous varieties of cultivated 

 pigeons are descended from a wild European species, 

 the blue rock-pigeon. 



The Woodpeckers (Pici) . These well-known birds 



ied owl (Bubo virginianus) . Adult female. Photo by Shufeldt. 



Questions on the Figure. What are the habits of the owl? Does 

 the figure show any structural adaptations to its known habits? 

 How does the standing position of the owl differ from that of most 

 birds? 



