EASTERN NIGHTHAWK 221 



her offspring for a roost in the nearby elm tree. She then visited 

 the roof only for short intervals at feeding times. On each succes- 

 sive day the young bird took longer and longer flights, and each day 

 I anticipated it would be my last opportunity to photograph and to 

 observe him. Much to my delight he continued to return, seeming 

 to enjoy my companionship. 



On August 15 he left with the other nighthawks of the vicinity 

 on their migration to the south. This unusual experience of having 

 the bird return to the roof gave me an unprecedented opportunity 

 to make a continuous set of daily observations and measurements of 

 a nighthawk living under normal natural conditions up to the time 

 it was 52 days of age. By this time the growth of the ju venal 

 plumage was completed and exchanged in part for the first winter 

 plumage. 



Plumages. — On the first day the young are able to stand upright 

 and are very active from the time of hatching. The eyes are open, 

 iris bluish black; skin darkly pigmented darker above than below; 

 bill "pale mouse gray"; tarsus and toes brownish drab. Down 

 present on both dorsal and ventral parts of the body. Down of the 

 ventral tracts pale gray shading to "pallid neutral gray" on the 

 belly ; chin gray, malar stripes and patch on the throat "dark mouse 

 gray," approaching black. Upper parts mottled and marbled, made 

 up of patches of pale gray and "dark mouse gray." In the region 

 of the nape and scapulars the down has a distinct "pale olive-buff" 

 tint. At the base of the beak the down has a tinge of buff. A 

 circular area about the anus, the outer part of the shanks, and fore 

 arm have patches of darker colored down. Patterns of dark and 

 white vary considerably in different young. The average length of 

 the down on the various parts of the body varies as follows: Crown 

 9, base of bill 4, region over eye 6, throat 12, belly 15, wing 11, and 

 region of anus 8 millimeters. 



On the third day the color of the bill has changed to a "deep 

 neutral gray," and the tarsus and toes become a dusky drab. Down 

 at the base of the beak, scapular region, and irregular patches of 

 the back has faded from the colors present in the day-old chick to 

 a "tilleul buff." Iris is now a clear brown instead of the bluish 

 black of the freshly hatched chick. 



At the age of 10 days the tarsus and toes are "deep Quaker drab," 

 bill "dark neutral gray," eyelids "light neutral gray." Exposed 

 portions of the eyes are noticeably greater. Down of the back much 

 worn and matted down, the feather papillae in the region of the 

 crown, wing coverts, scapulars, and rump now more conspicuous 

 than the down. The tips of the feathers of the back are unsheathed 

 and exhibit a black and cinnamon color. The color pattern of the 

 back is completely lost since the appearance of the feather papillae 



