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ZOOLOGY 



Ptarmigan in summer. Davison, Zoology. 



are best known to us are the hawks, 

 the condor, with its great sweep of 

 ten feet from wing to wing, and 

 the eagle. To the hawks belong 

 two birds which are, because of their 

 habits, harmful to man. They are 

 the sharp-shinned hawk and Coop- 

 er's hawk. 



IV. Waders. — These are birds 

 with unusually long legs and long 

 necks, the latter character being a 

 natural correlation of greatest ser- 

 vice in food getting. Examples are 

 the mud hen or coot, the snipe, 

 crane, heron, and stork. The last 

 two are the giants of the group. 



The Swimmers and Divers. — • 

 Birds placed in these orders have 



snow which surrounds it; in 

 the spring it molts, turning 

 to a gray and white, thus re- 

 sembling the lichens among 

 which it feeds. 



III. Birds of Prey. — 

 These birds are character- 

 ized by the strong hooked 

 beak, adapted to tearing, and 

 by the sharp claws, which are 

 curved and strong. The need 

 of a gizzard, which is a promi- 

 nent part of the digestive 

 tract in a grain-eating bird, 

 has here almost completely 

 disappeared, the crop serving 

 to macerate the food. Owls 

 show this use of the muscu- 

 lar gullet and crop, for the 

 hair and skeletons of the mice 

 which form their prey are 

 ejected in a small ball, by 

 means of this muscular organ. 

 Members of this group that 



Golden eagle (Aquila chrysactos). North Amer- 

 ica and Europe. Copyright, 1901, by N.Y, 

 Zoological Society. 



