igO THE SOCIAL LIFE OF ANIMALS 



the mating period BY, which was top bird in the 

 pre-mating flock of females, and RY did not pair off 

 with any of the males. Again I do not know why. 

 After the experiment was finished RY was carefully 

 autopsied and we could find no evidence of any- 

 thing physically abnormal. When the sexes were 

 again segregated RY was the top-ranking bird among 

 her fellow females, and remained so. She was seen 

 to have loi contacts with BY, the former alpha bird, 

 and to win 83 of them; she had 77 observed contacts 

 with BB, which had formerly been second from the 

 top, and defeated her 53 times. In the pre-mating 

 period RY lost two combats for each that she won; 

 in the post-mating flock she won five contacts for 

 each that was lost. 



This raises in a rather dramatic fashion questions 

 as to what qualities make for a dominant bird. This 

 problem is not yet solved. With these birds, social 

 rank is in part a matter of seniority. Mature chickens 

 usually dominate immature ones and maintain their 

 dominance long after the former youngsters have 

 become fully mature and possibly physically able to 

 displace the senior members. This is good evidence 

 that memory of former defeats plays a role in main- 

 taining the social order once it is established. When 

 chickens strange to each other are put together for 

 the first time dominance usually goes to the bird 



