76 BEHAVIOR OF PIGEONS. 



Mar. 15. Contrary to usual behavior, the male sat every night beside the female 

 in the nest-box. To-day he tried to copulate with the female while she was sitting on the 

 egg. He tried this also yesterday morning. The first egg is due to hatch 2 to 3 days hence. 

 Probably the male will be unable to feed the young in case they hatch. The female is 

 faithful. 



Mar. 16. The male was taken away because he had succeeded in getting the female 

 weaned from the nest so that she would stay with him on the floor and copulate. After 

 removing him the female sat one day and night; but on the next day, when the first egg 

 was due to hatch, she refused to sit another moment. I shall keep this pair apart for a 

 while to see if they will fall into regular work next time. (R 33.) 



GEOPELIA HUMERALIS. 



The eggs of the first two cycles (of 1906) were thin-shelled and were broken 

 within 2 days after the second eggs were dropped. The cycles were terminated 

 immediately. In the first case, a renewal started immediately; but it was delayed 

 several days in the second case, probably owing to sickness of the female. 



The male is already in the nest calling the female to a new nesting cycle. How quickly 

 the renewal of these things takes place. At once the male invites a renewal of the nesting 

 cycle. The female, however, does not seem to feel quite well perhaps somewhat exhausted, 

 and possibly her digestion is not normal. I saw her throwing up her food the evening 

 after she laid the first egg. (R 29.) 



In the third cycle of the above pair both eggs failed to hatch, and they were 

 deserted on the seventeenth day, shortly after they were due to hatch. Since the 

 period of sitting continues (with feeding of young) for a week after the eggs hatch, 

 evidently the termination of the activity is connected with the failure of the eggs 

 to hatch. 



PASSENGER-PIGEON MALE AND RING-DOVE FEMALE. 



FIRST CYCLE. 



The account starts on January 9, when the female was expected to lay. The 

 pair had evidently been mated previously, and had entered the first part of the 

 mating period. This record is unusual in the length of this mating period; it 

 covers 17 days, exclusive of that portion preceding the record. The female per- 

 sisted here in continuing the incubation activities for 11 days in spite of a number 

 of defective conditions. Only one egg was laid, which was broken after 3 days; 

 she was subject to the sexual attentions of the male; probably the male failed to 

 alternate in the task of incubation; she was driven from the nest for 5 nights and 

 forced to take the perch. This driving finally broke up the incubating impulse, 

 and the female took the perch of her own accord and began to receive the male. 

 The male participated in the incubation regularly until the egg was broken (3 

 days). Although no definite statements are made, it is probable that this event 

 very soon terminated the incubating impulse of the male. He certainly made 

 sexual advances to his mate, and it is highly improbable that he continued to 

 alternate with the female without the fact being noted. 



On Jan. 9 this female was expected to lay for the first time in life. I found her on the 

 nest at 3 h 50 m and kept watch in order to get the exact time. She behaved as if she was 



