FAMILY CATHARTIDAE 159 



Resident throughout the isthmus, except in the very high moun- 

 tains, found mainly in settled areas ; absent or rare in regions of un- 

 broken forest. Isla Coiba; islas Pacheca, Saboga, Bayoneta, Sefiora, 

 Pedro Gonzalez, and San Jose, in the Archipielago de las Perlas ; 

 Isla Taboga ; Isla Gobernadora. 



The black vulture, recognized throughout tropical and subtropical 

 America as an efficient scavenger, is one of the prominent species in 

 settled areas, found singly or a few together around country houses 

 or congregated in dozens about abattoirs or refuse dumps near 

 villages. They enjoy protection in general through recognition of their 

 efficient services in disposal of offal, though in recent years there has 

 been consideration of the possibility that they may be carriers of 

 some animal diseases as they move from carcasses of dead animals to 

 rest near living ones in corrals and farmyards. These are matters 

 that are under special study. 



Where black vultures become unusually tame they often enter 

 familiarly in patios, or come near buildings, where care must be used 

 to prevent their thievery of meats or other human food. And it is 

 necessary always, where they have become more or less domestic, for 

 the naturalist to guard his specimens. In some village areas, where 

 there is dependence on rain water caught by drain spouts from build- 

 ings, these vultures are distinctly troublesome when abundant, as 

 their droppings may pollute the metal roofs, and so wash into the 

 cisterns. 



In flight these birds flap the wings rapidly several times, spread 

 them stiffly to glide, then flap again, a method of alternately different 

 movements that serves to identify them at any distance from the 

 steadily soaring turkey vultures. However, black vultures also are 

 adept at soaring in rising air currents without change to flapping 

 wings. In such a manner they often continue for long periods, 

 sometimes rising until they may be barely seen against the sky. 



Keen vision is proverbial among vultures as they detect sources of 

 food at distances that seem almost incredible. In work on the San 

 Bias coast at Mandinga, in 1957 I saw none of this species until one 

 morning I spread bodies of small birds that I had skinned for speci- 

 mens on the old abandoned air strip in order to secure a check on 

 the forms of turkey vultures present. At noon I saw first one black 

 vulture and then another in descent at a sharp angle from high in 

 air, and walked out to find that 9 had arrived, and that all of the 

 meat had been eaten. During the month that I lived there I saw only 

 one other bird of this species. 



Near the coast black vultures watch the beaches for dead fish 

 cast up by the waves. If tide is rising so that the waves wash over 



