NO. 6 REVISION OF AMERICAN VULTURES WETMORE II 



Remarks. — This race and jota are less black on the lower surface 

 than ruficolHs. While birds in the range outlined are similar in 

 grayish-white markings on the wings to jota, and so have been in- 

 cluded under that name by recent authors, they differ definitely in 

 smaller size. The coastal area that they inhabit from Chile northward 

 appears to be invaded by wandering individuals of the inland race 

 jota, which has led to confusion in understanding. It may be supposed 

 that the population is one adapted to maritime conditions influenced 

 by colder oceanic waters. 



Those found along Peru and Ecuador appear smaller than those of 

 the Falklands and may prove separable as another form when more 

 is known about them. 



CATHARTES BURROVIANUS Cassin: Yellow-headed Turkey Vulture 



Bare area of front and side of neck with numerous small papillae 

 or caruncles, mainly low down toward the feather line, in lesser 

 number toward the base of the head ; prominent in freshly killed birds, 

 visible in museum specimens as small, wartlike processes ; hindneck 

 feathered to base of cranium ; in life, head and neck yellow and 

 orange, varied by prominent blue markings bordered more or less 

 with green on the crown. Color of dorsal surface dull black, with 

 feathers tipped prominently with fuscous and fuscous-black ; brown- 

 ish black below ; metallic bluish or greenish sheen less extensive than 

 in the larger species with similar head colors. Development of the 

 neck papillae begins in young birds as soon as they are on the wing. 



Until I collected specimens in western Panama in 1948, which led 

 to the proper allocation of Cassin's ancient name burrovianus of 1845 

 (Wetmore, 1950, pp. 415-417) this species was believed to be re- 

 stricted in range to South America. In the abundant material now 

 available from the region between northeastern Mexico and northern 

 Argentina two geographic races distinguished by differences in size, 

 may be recognized, 



CATHARTES BURROVIANUS BURROVIANUS Cassin 



Cathartcs Burrovianus Cassin, Proc. Acad. Nat. Sci. Philadelphia, vol. 2, no. 8, 

 March-April 1845, p. 212. (Near Veracruz, Veracruz, Mexico.) 



Size small ; wing 432 to 459 mm. 



Measurements.— M.2\ts (10 specimens), wing 432-455 (445.4), tail 

 195-225 (207.2), culmen from cere 19.6-23.3 (21.3), tarsus 51.1-59.1 

 (57.1), approximate width of central rectrix 42-49 (46.3) mm. 



