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 Reef 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 
joiming 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 day :— 
