CLASS AVES. BIRDS 



453 



pears to have been killed. Auks were de- 

 stroyed for their feathers, and their eggs 

 were used as food. All that remain today of 

 the great auk are about 80 preserved speci- 

 mens, 75 eggs, and some 25 skeletons. 



Figure 325. Vulture showing naked head, and 

 beak slightly hooked. (Photo by Gross. Courtesy of 

 Nature Magazine.) 



Birds of prey 



The falconlike birds are busily engaged 

 by day, and the owls by night, seeking whom 

 they may devour. The diurnal birds of prey 

 possess, in most cases, powerful wings, a 

 stout hooked bill with a cere at the base, and 

 strong toes armed with sharp claws. The 

 vultures (Fig. 325) have weak feet and 

 live on carrion (dead animals); they are 

 especially valuable as scavengers, in warm 

 countries, where they remove dead bodies 

 before they become a health hazard. Some 

 other species that live in the United States 

 are the swallow-tailed kite, osprey, bald 

 eagle (Fig. 328), red-tailed hawk, Cooper's 

 hawk (Fig. 322), sparrow hawk, and golden 

 eagle. 



Owls (Fig. 305) are nocturnal birds of 

 prey. They possess large rounded heads, 

 strong legs, feet armed with sharp claws, 

 strong bills with the upper mandible curved 

 downward, large eyes directed forward and 

 surrounded by a radiating disk of feathers, 



and soft fluffy plumage which renders them 

 noiseless during flight. Owls feed upon mice, 

 rats, and other small mammals, as well as 

 insects, birds, and fish. The indigestible 

 parts of the food are cast out of the mouth 

 in the form of pellets. Most species of owls 

 are beneficial to man. Among the well- 

 known North American species may be 

 mentioned the barn owl (Fig. 305), screech 

 owl (Fig. 327), great horned owl (Fig. 

 326), and burrowing owl. 



Game birds 



Many kinds of birds are hunted for sport. 

 Among these are the wild turkey, bob-white, 

 pheasant (Fig. 305), ruffed grouse, prairie 

 chicken, etc. Game birds are as a rule ter- 

 restrial, but manv roost or feed in trees. 

 The members of one or more families often 

 remain together as a covey, and in some 

 species the coveys unite to form large flocks. 



Cuckoos, road runners, 

 hummingbirds, and others 



Cuckoos are mostly tropical birds. The 

 majority do not build a nest, but lay their 

 es2S in the nests of other birds. This is not 

 true, however, of the North American spe- 

 cies. Their peculiar vocal powers have given 

 them their common name. The chimney 

 swift formerly made its nest in hollow trees, 

 but now usually frequents chimneys (Fig. 

 320). When in the open air, it is always on 

 the wing, catching insects or gathering twigs 

 from the dead branches of trees for its nest. 

 The twigs are glued together with saliva and 

 firmly fastened to the inside of the chimney, 

 forming a cup-shaped nest. Certain species 

 of swifts inhabiting the East Indies make 

 nests of a secretion from the salivary glands, 

 producing the edible birds' nests relished by 

 the Chinese. 



The road runner is an inhabitant of des- 

 erts in the southwestern United States, 

 where it lives among the cacti, sagebrush, 

 and mesquite. It is a long, slender bird and 



