FAMILY CATHARTIDAE 167 



Smithsonian Misc. Coll., vol. 106, no. 1, Aug. 5, 1946, pp. 24-25) was 

 interpreted then as a record of a wanderer from some nearby South 

 American area, since that was the known range of this race at the 

 time. Others of this subspecies were found in Darien two years later, 

 and in subsequent seasons the race ruficollis, little by little, was traced 

 westward across the isthmus. As I have found it within 30 kilometers 

 of the Costa Rican border, below Alanje in western Chiriqui, it seems 

 probable that it may range farther north in Central America. The 

 records listed are of birds collected, and of others observed close at 

 hand so that the head marking was seen clearly. It remains to deter- 

 mine the identity of the resident subspecies of the Caribbean coast in 

 western Colon and Bocas del Toro. 



While these birds have the usual habit of the species of feeding on 

 carrion, I was interested to find the crop of one killed at La Jagua 

 late in March filled with bright yellowish-orange pulp from the large 

 fruits of the spiny-trunked corozo palm. I was told that this was 

 a common source of food for vultures. The bird that I examined 

 personally was of the resident race ruficollis. It is not certain that 

 migrant aura from the north shares this habit. 



Though there is no detailed information regarding the breeding of 

 this race in Panama, other than that I was told that they used hollows 

 in tree trunks on, or very near, the ground, it is assumed that nesting 

 here is like that elsewhere in the range of the race. In general, two 

 eggs are laid on whatever natural accumulation of decayed wood, 

 humus, or earth there is in the hollow selected as a nest shelter. Oc- 

 casionally one egg or three may be encountered. In color the eggs 

 are dull white to creamy white, marked more or less heavily with spots 

 and blotches of light to very dark brown. 



The young of ruficollis, when fully grown and able to fly, have 

 head and bill dull black, the former covered with short, blackish 

 down, except for the spot of dull white on either side of the nape. 

 When nestling turkey vultures are approached they often assume a 

 grotesque attitude, with arched neck, head bent down so that the 

 bill touches the breast, and partly feathered wings spread, while they 

 utter a peculiar cat-like hiss. At intervals the tip of one wing is 

 struck sharply against the ground, and the note changes to a rough 

 growl, the sound and the note coming abruptly in startling fashion. 

 The vocal efforts of adult birds are limited to low, barely audible 

 hissing sounds. 



