BLACK VULTURE 33 



"chestnut", "liver brown", or "chocolate", but sometimes in lighter 

 browns, "russet" or "tawny", with occasionally a few "Quaker drab" 

 spots. One very pretty egg is heavily blotched with "pale purple 

 drab", with a few spots of "bay"; another is heavily blotched and 

 finely spotted with "burnt sienna"; but such eggs are exceptional. 

 The measurements of 51 eggs average 75.6 by 50.9 millimeters; the 

 eggs showing the four extremes measure 90.5 by 55.9, 75 by 56, 66.5 

 by 51, and 67.3 by 47 millimeters.] 



Young. — The incubation period is variously stated to be anywhere 

 from 28 to 39 daj^s ; and both parents assist in the incubation. Bay- 

 nard (1909) watching 21 nests found the incubation was usually 

 28 to 29 days, in one case 30 days. Edward S. Thomas (1928) 

 reports it as about 39 days in one case. The young, helpless at first, 

 may stray a little from the nest on the ground at a comparatively 

 early age, but, according to Baynard (1913), they are about 14 

 weeks old before they are able to fly. Simmons (1925) quotes H. J. 

 Kofahl's statement that the young remain at the nesting site for 

 about 60 days. Howard Lacey (1911) says "the young feign death 

 when disturbed." 



The Rev. James J. Murray, of Lexington, Va., gives the following 

 interesting account of an experience with young birds on the summit 

 of House Mountain in Virginia, an elevation of about 3,000 feet : 



The nest cavity was under a pile of huge boulders. The cave had an open- 

 ing above large enough for a man to crawl into, and tunnels from two sides 

 at the ground level * * *. One of the parent birds flew out of the upper 

 opening as we approached. There were two young birds, one somewhat larger 

 than the other. They appeared to be three or four weeks old and to weigh 

 about three pounds. They had no feathers and were covered with a thick 

 down of cream buff color, almost reddish above. As we went into the hole 

 they began to vomit large pieces of meat, almost choking in the effort, and 

 continued to do so at intervals as long as we were there. They constantly 

 made a loud blowing noise through slightly opened mouths. It was not a 

 hiss but more like the noise of a bellows. At every effort to get them out into 

 the open they scrambled back into the darkness, jamming themselves under 

 the overhanging rocks and burying their heads in the cracks. When we 

 finally pulled them out to the end of the tunnel in a vain effort to get a good 

 picture in the dim light, they fought each other fiercely and pecked at our 

 hands. 



Edward S. Thomas (1928) describes the feeding of the young as 

 follows : 



The adult bird lowers its bill to the young, which immediately inserts its 

 beak between the opened mandibles of the adult. The adult, with or without 

 a perceptible gulping movement, regurgitates the food, which is eaten by the 

 young with a nibbling movement of its mandibles. We were certain that 

 at times the adult extruded broth-like drops of liquid which the young secured 

 from the scarcely opened mandibles of the old bird. At other times the young 

 birds obtained the food from the middle part of the adult's beak, but the 



