2 THE AUDUBON Bil eke 
and obtained a fairly complete photographic record of the development of 
the young. 
The nest in a vine-covered trunk of a tulip tree was located March 24 
about twenty-five miles south-east of Nashville, Tennessee, near the Smyrna 
Army Air Field. It was situated in an openly-wooded area of approxi- 
mately fifteen acres which was surrounded on all sides by cultivated fields. 
The cavity, the entrance to which was some eight feet above ground, 
measured about three and one-half feet long by one and one-half feet wide 
and was practically divided into two chambers by a slab of wood projecting 
from the inside of the trunk. The rubble of dead sticks and rotten wood 
chips on the floor of one of the chambers served as the nest. Although 
there was ample room for the young or adults to pass from one part of 
the cavity to the other they were always found in the section that had 
contained the eggs. No droppings or other evidence of occupancy were 
ever noted in the unused portion; and the nestlings, even at an early age, 
would scramble to the occupied section if placed in the other part. 
Two eggs were in the cavity on March 24. They were bluish-green and 
irregularly spotted, more profusely toward the larger end, with rich brown. 
It was not possible to accurately determine the date of their laying; but 
by using thirty-five days as the incubation period — a figure supplied by 
Mr. H. O. Todd, an odlogist of Murphreesboro, Tenn. — and the fact that 
the eggs hatched before April 14, it was assumed that they were laid 
sometime during the first week in March. 
On April 14 two young about five inches in length were found in the 
cavity with the remains of about three-fourths of an egg shell and another 
smaller piece. Noticeably different in size and weight, the nestlings were 
covered with woolly, tawny-colored down. The skin of their heads was 
black; their legs and feet, gray. Vestiges of the egg-tooth were visible 
on the beaks of both; and, although their movements were feeble, they 
frequently uttered a hoarse, cat-like note. The sex of the nestlings was 
never determined as the only external characteristics which set them apart. 
were the difference in size and the fact that the larger had more down on 
the top of its head than did its nestmate. Whether these points were a 
clue to the sex of the young or simply due to a difference in age or to some 
other reason I was unable to decide. 
A week later the young vultures had increased greatly in size and 
weight and had become quite aggressive, attacking my hand with a snap 
of the beak and an angry hiss whenever the opportunity presented itself. 
When placed on a dead log for photographing the larger nestling spread 
his wings and shifted his position until the sun was at his back, remaining 
thus for several minutes. When the young were about five weeks old they 
exhibited a new type of behavior. Up to this time they had always greeted 
my arrival with their peculiar whining growl and vigorously objected to 
being handled. Now, whenever I entered the cavity, both birds would stand 
motionless in the nest with their heads thrust into crevices in the wood of 
the inside of the tree. When I touched them, they would whirl in a flash, 
rush at me, then quickly resume their original position. 
