24 G. E. H. BARRETT-HAMILTON [july 



As the season advanced and the area of ground occupied by the 

 rookery increased, it was obvious that the small harems seen by me on 

 June 20 were merely the nuclei of larger gatherings, which gradually 

 increased and swelled so much as to coalesce and form the rookery as 

 seen in its completed aspect. Thus those bulls which were at first 

 obliged to sit outside the harems were for the most part absorbed in 

 the breeding-grounds, and, as at the Eeef section of the rookery, 

 the bachelors found no difficulty whatever in wandering among 

 the cows. 



By the 29th June the females had so increased in numbers as to 

 be quite out of the control of the bulls, and they were then able to 

 make their way to or from the sea with little or no interruption. 

 Many of them lay in loosely scattered patches with no bull to attend 

 on them. 



Yet the strange thing was that, although in several cases the 

 harems of individual bulls grew to such unwieldy proportions that the 

 bulls were powerless to prevent the cows from leaving them or from 

 joining other bulls, there were all the time other bulls which, either 

 from the position which they had selected or from other reasons, were 

 never able to secure a harem. Their desire was evidently to occupy 

 some particular position already commanded by a stronger bull. This 

 being impossible, they sat or slept out of reach of their enemy, and 

 made no attempt, as a rule, to collect a harem for themselves. 



Occasionally, however, one of these solitary bulls would become 

 infuriated, and, charging down upon the harems, would seize a female 

 and run away with her. The female, however, thus captured invari- 

 ably, as far as I could see, returned to her old place at the first 

 opportunity. 



Although not possessing harems, these bulls were by no means 

 idle, for they often had a single cow with them, which no doubt had 

 been dissatisfied with her treatment at the hands of the master of her 

 own particular harem, and had sought another lord. The visits of such 

 cows to these outlying bulls appeared to be of a merely temporary 

 nature, and I think they returned to their own harem when satisfied 

 by the accomplishment of their object in leaving it. 



Some of the harems which I kept under close observation for 

 several days will illustrate these points. 



There were at the south end of Kishotchnaya during the early part 

 of the season four bulls by themselves; one of these had on the 29th 

 June about sixty-three females and another twenty ; while not far from 

 them sat three younger bulls, one alone and the other two with three 

 females. 



The following table shows the increase in the two larger harems 

 from day to clay : — 



