8 BEHAVIOR OF PIGEONS. 



The hypothesis that the sexual impulse arises relatively automatically with 

 each bird does not imply that the two birds do not stimulate each other to any 

 extent. While synchronization is normally effected, yet exceptions occur and the 

 cycle may progress with one bird lagging a few days behind the other. Neither 

 will a bird always remain in the first stage of readiness until the succeeding activ- 

 ities of the cycle are released by the reciprocal activity of the mate. Occasionally 

 the cycle may progress to completion without the cooperation of a partner. These 

 statements are illustrated by the following excerpts from the manuscripts. 



A pair of Geopelia humeralis were put together on Dec. 23, 1905. On Dec. 26 it 

 was noted that the male had every day shown some interest in nesting, but that the female 

 did not seem to be ready. On Jan. 9, 1906, it was noted that the male had kept up his 

 endeavors to interest his mate in a nest, but that so far she had remained indifferent. The 

 first egg was laid on Jan. 21. Allowing 7 to 8 days as the normal time between the begin- 

 ning of mating and the laying of the first egg, there was a period of about 3 weeks in which 

 the female remained indifferent to the advances of the male. In the third cycle for this 

 pair the female resisted the male's attentions for several days, while in the second and 

 fourth cycles both birds seemed to be ready simultaneously. 



In a bronze-wing pair the male took the initiative in all five cycles. The period of femi- 

 nine resistance varied from 1 to 7 days. On the last cycle the pair was separated on March 

 16, 1906, just as they were beginning a new cycle. After a separation of 15 days they 

 were brought together for a short time and courting began immediately, both birds seem- 

 ing to be ready to continue the cycle. They were tested from time to time up to April 

 28, and both exhibited some interest in mating. They were now left together permanently 

 and the new cycle started at once. Both birds thus remained in a state of more or less 

 readiness for a period of 45 days. 



A male mourning-dove (Zen. 3) was paired with a white ring-dove (W 1) on December 

 20. The female was eager to mate, and tried all possible ways to ingratiate herself in the 

 favor of the male. He refused to have anything to do with her until 12 days later. On 

 this date (Jan. 1), the female advanced to within a few inches and began billing her wings, 

 bowing, cooing, and casting amorous glances. He soon began to be attracted, billed his 

 wing, and showed that he was yielding. When she touched his head with her beak he 

 repelled her by pecking because of fear. After these maneuvers were continued for 15 

 or 20 minutes he finally had the courage to take her beak in his, and thereupon the con- 

 summation followed quickly. I am quite certain that this was the first time that a union 

 had taken place. On Jan. 5, W 1 is still doing most of the courting. She is wonderfully 

 persistent, taking no discouragement from any rebuff. On Jan. 20 I saw the male court- 

 ing the female for the first time. This pairing was never successful. Although unions 

 occurred, the eggs did not develop for lack of fertilization, and the male took no part in 

 incubation. After 3^- months (of trial) he was given another female. 



A young male fantail was paired on Aug. 13 with an impure fantail female which 

 had previously mated and had been incubating eggs with another female. Two days 

 later this female took the initiative and attempted to mate with the male. He was quite 

 bashful at first, and although pleased with the advances, appeared to fear to let her come 

 very near. He fought her off the stand and would not let her remain a moment in the 

 cot. During the day he became more enamoured and by degrees suffered her to approach 

 him, but always retreated at the moment she offered her beak, or else attacked her as if 

 not yet quite sure that she could be trusted. This behavior continued throughout the day. 

 On the following day, they were both coquetting and billing, and seemingly fully mated. 



