A REVISION OF THE AMERICAN VULTURES 

 OF THE GENUS CATHARTES 



By ALEXANDER WETMORE 

 Research Associate, Smithsonian Institution 



Turkey vultures, found widely throughout the Americas, though 

 easily recognized in Hfe or when freshly killed, pose many dififiiculties 

 in identification when preserved as museum specimens. The color 

 differences of the bare head and upper neck that separate the species, 

 and in the case of the red-headed group some of the subspecies, 

 change soon after death to a dull hue discouragingly similar in all. 

 My personal interest in these birds began in 1920 when I first en- 

 countered the yellow-headed vulture in life in the Chaco of Argentina 

 and Paraguay, and in the report on that expedition I ventured to 

 publish a synopsis that covered what I had been able to learn of the 

 genus as a whole (Wetmore, 1926, pp. 86-91). The subject has 

 remained one of intriguing interest, in large part because of its diffi- 

 culties, and I have continued to examine birds of the genus whenever 

 possible. A preliminary account of the yellow-headed group has been 

 covered in another study (Wetmore, 1950, pp. 415-417). The account 

 that follows is based on data from several hundred museum skins, 

 in addition to many observations on living individuals that I have seen 

 and have collected during my expeditions in tropical regions. 



In these studies I have been indebted to many individuals, among 

 whom I should mention especially Mr. J. D. Macdonald and other 

 authorities of the British Museum (Natural History) for privileges 

 in connection with their collections, in particular the material that 

 had been studied by Harry Kirke Swann. Dr. G. Rokitansky of the 

 Naturhistorisches Museum in Vienna made arrangements that, in his 

 absence, allowed me to examine the series of yellow-headed vultures 

 in that institution. The collections in the American Museum of 

 Natural History and the Chicago Natural History Museum have been 

 of repeated assistance. I have to thank especially Dr. George H. 

 Lowery, Jr., for the loan of specimens that included two of the new 

 form described in this paper. Dr. Emerson Kemsies, in charge of 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 146, NO. 6 



