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BIRDS 
Sailing birds, like the gulls, have long, slender wings, while 
ground birds, like the partridge and pheasant, have short 
wings capable of rapid, short flights. Those birds that make 
the most use of wings have them best developed. An 
example of underdevelopment, which has been increased by 
domestication, is seen in the domestic fowl, a ground bird, 
Figure 95. — Herring Gulls. 
Note the different position and shape of the wings. 
which makes little use of its flying powers, and is incapable 
of sustained flight. 
The legs of birds also have many variations. In the case 
of the eagles, hawks, and owls there are powerful claws for 
seizing and holding prey, while ducks and geese have long 
and webbed toes, adapted to swimming. Seed-eating birds 
have weak claws which serve merely for perching. Chimney 
swifts, that spend most of their time in flight searching for 
food, have well developed wings, and feet used for clinging. 
Study Figures 96 and 97. 
