THE WORLD'S BIRDS. 



AMERICAN VULTURES (Cathartidte). 



DIAGNOSIS. Vulture-like birds of prey, with pervious 

 nostrils and all front toes webbed at base. 



SIZE. From that of a fowl to larger than a swan. 



FORM. Bill moderate or short, strongly hooked, with 

 no internal division between nostrils, and corner 

 of mouth high and terminating before eye ; feet 

 with hind-toe so short as to be useless, and all 

 front toes webbed at base. Wings large, blunt ; 

 tail usually short. Eyebrows not prominent as 

 in other birds of prey, and thighs closely feathered, 

 not clad in long plumes. 



PLUMAGE AND COLOURATION. Feathering sombre and 

 uniform, generally black ; no sexual difference in 

 colour or seasonal change, but young often unlike 

 adults. Head always bare of feathers. 



YOUNG. Helpless and clad in white down. 



NEST. Usually none ; the eggs being laid on the 

 bare ground or on rocks, or in a hollow tree. 



EGGS. One or two ; pale-coloured, uniform or 

 spotted. 



INCUBATION. From about a month to nearly eight 

 weeks (Condor). 



COURTSHIP. In the Black Vulture (Catharistes atratus] 

 the male erects and expands his wings. 



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