386 ZOOLOGY 



storks and gannets, flamingos, and others. The order 



relatives contains very divergent elements, and should 



perhaps be divided. They are wading or swim- 

 ming birds, and are best recognized by the pe- 

 culiar features of the several genera. They are 

 associated together on anatomical grounds, and 

 on the same grounds kept entirely apart from 

 the cranes and some other birds with which 

 they might be confused. The birds afford many 

 examples of convergent evolution, in which 

 different groups have produced species adapted 

 to the same general mode of life, and conse- 

 quently superficially more or less similar. 



Ducks, (i) Anseriformes. Ducks, geese, and swans, fa- 



nd miliar to all. They are most easily recognized 



by the form of the bill. The young are 

 covered with down, and are able to swim soon 

 after hatching from the egg. Nearly all have 

 webbed feet. 



Birds of prey (/) Falconiformes. Also called Raptor es, or birds of 



prey; including the hawks, eagles, vultures, and 

 their relatives. The hooked bill is character- 

 istic, though it is found in other birds, such as 

 the owls and parrots. The owls, though 

 resembling the hawks in their flesh-eating 

 habits and the form of the bill, are really not 

 related to them ; in fact, modern students of 

 birds associate the owls more closely with the 

 humming birds than with the Falconiformes. 

 The national bird of the United States is the 

 so-called Bald Eagle, Halitztus leucocephalus, 

 -the specific name meaning "white-headed' 1 

 in Greek. It is widely distributed over our 

 country, but by no means peculiar to it. 



