BIRDS OF NORTH AND MIDDLE AMERICA 9 



although some of the Old World vultures are but little inferior in 

 this respect. The remaining members of the group, however, are 

 birds of only moderate size, those belonging to the genera Cathartes 

 and Coragyps but httle exceeding the larger hawks in bulk. 



The family (as well as the suborder, to which it is exactly equivalent 

 among Hving birds) is peculiar to America, where it is represented by 

 five genera (four of tliem monotypic) and seven or eight species, which 

 inhabit all but the colder portions of both continents. 



"They lack the strength and spirit of typical Raptors, and rarely 

 attack animals capable of offering resistance; they are voracious and 

 indiscriminate gormandizers of carrion and animal refuse of all sorts — 

 efficient and almost indispensable scavengers in the warm countries 

 where they abound. They are uncleanly in then* mode of feeding; 

 the nature of their food renders them iU-scented, and when disturbed 

 they eject the fetid contents of the crop. Although not truly gre- 

 garious, they assemble in multitudes where food is plenty, and some 

 species breed in communities. When gorged, they appear heavy and 

 indisposed to exertion, usually passing the period of digestion motion- 

 less, in a Hstless attitude, with their wings half spread. But they 

 spend most of the time on wing, circling high in the air; then- flight is 

 easy and graceful in the extreme, and capable of being indefinitely 

 protracted. On the ground, they habitually wall^ instead of pro- 

 gressing by leaps.^ Possessing no vocal apparatus, the vultures are 

 almost mute, emitting only a weak hissing sound." (Coues.) 



KEY TO THE GENERA OF CATHARTIDAE 



a. Commissure short, the angle of rictus situated nearly beneath posterior end of 

 nostril; entire neck, except extreme lower portion, bare; cervical vertebrae, 

 17; dorsal vertebrae, 3; coccygeal vertebrae (exclusion of pygostyle), 6'; 

 basi-temporal region of skull deeply excavated, the lateral portion developed 

 into prolonged occipital processes i"; postacetabular ilia rising above synsa- 

 crum to meet one another in median line; rings at bifurcation of bronchi! 

 thick and close together; bronchii incomplete internally; eggs immaculate. 

 h. Cere decidedly shorter than rhinotheca of maxilla; bill very strong, with 

 culmen distinctly arched from base; adult male, at least, with a con- 

 spicuous "comb" or erect compressed caruncle surmounting the cere; 

 plumage commencing on lower neck with soft and downlike or broad and 

 blended feathers. 

 c. Size very large (wing more than 7G0 mm.); plumage (in adults com- 

 mencing with a conspicuous collar of soft, cottonlike white downlike 

 feathers; "comb" (present in adult male only) attached to entire length 

 of cere and backward to at least middle of crown; adult male with a 



* When hurried, however, they progress by awkward springing leaps, assisted 

 by their half-opened wings, in a manner not materially different from hawks or 

 eagles under similar circumstances. 



'Shufeldt, New York State Mus. Bull. 130, 1909, 25. 



•0 Beddard, Proc. Zool. Soc. London, 1903 (2), 386-392. 



