216 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



9 : 00 a. m. The nighthawks have been quiet since 4 : 46 a. m. For 

 the greater part of the time the female has been motionless, with 

 her eyes closed, but at intervals she opens her eyes wide in response 

 to some unusual disturbance. She did not leave to feed, as is usual 

 for her to do each morning. 



9 : 10 a. m. The female shifted her position and turned her eggs. 

 I left the blind at 9 : 15 a. m. and my place was taken by student 

 observers, who took notes in relays until my return in the evening. 

 They reported no activity on the part of the male. He remained 

 on his perch in the elm throughout the day. The female did not 

 leave the nest but merely shifted her position slightly from time 

 to time in adjusting her eggs. When the heat was excessive she 

 panted vigorously in order to adjust her body temperature. 



7:30 p. m. When I arrived at the roof the sun was shining on 

 the nesting female. Her eyes were opened as I approached the nest 

 but were again closed after I had entered the blind, 



8 : 05 p. m. The first peent call of the nighthawk is heard from 

 the male nighthawk, perched in the elm tree near the school build- 

 ing, where he had retired at 4 : 46 a. m. 



8:09 p. m. Male leaves his perch in the elm. Simultaneously an- 

 other nighthawk appears from the elms farther clown the street. 



8 : 46 p. m. The male alights near the nesting female. 



8 : 47 p. m. The female, facing toward the western sky, opens her 

 eyes wide and turns from side to side. With this preliminary 

 action repeated several times, she leaves the nest. The male remains 

 within a few inches of the nest but makes no attempt to incubate 

 the eggs. He merely serves as a guard while the female is away. 



8:48 p. m. The male leaves the roof for a moment, uttering the 

 sharp peent calls, and then returns to take up his position near to 

 the nest. 



8 : 50 p. m. The female returns to the nest after being away only 

 three minutes. The male was quiet while on the roof alone, but as 

 soon as the female returned he started his guttural notes. 



8 : 58 p. m. The male takes leave without any ceremony and flies 

 to his perch in the elm tree. 



9 : 01 p. m. The female leaves the nest quietly. 



9 : 22 p. m. No nighthawks have been seen or heard during the past 

 20 minutes. The female unannounced returns, after her quest for 

 food, to brood her eggs for the remainder of the night. 



Activities began again at 3 :14 a. m. the next day, and the program 

 was in all essentials similar to that recorded for June 20. Although 

 a large series of such observations were made the male never was 

 seen to incubate the eggs, but he regularly visited the nesting female 

 each morning and evening. Sometimes, especially in very cloudy 



