EVERMANN — STELLER SEA LION ROOKERY 
19 
As a result of counting the animals six to nine times in each of the 
groups we agreed that the total number was between 1500 and 2000, 
with the probability that 2000 is more nearly correct. The two things 
that impressed us most were the preponderance of adult bulls and the 
scarcity of pups. The light keeper, J. 0. Becker, estimated the number 
of bulls at twice the number of cows. This may be an overestimate, 
but it is quite conservative to say that the number of adult bulls is at 
least half as great as the number of cows. The number of young bulls 
was also large. The greatest number of cows seen in any one harem 
was 7 ; usually there were only 1 to 5. 
Very few pups could be seen on the rocks, certainly not more than 
100 all told. But in the little nooks and coves, both in the water and 
on the beach, fully as many more w^ere seen dead or dying. In one 
place we counted 34 dead pups in the water washing back and forth 
with the waves. In another protected cove were 24 pups, 19 dead and 
5 evidently dying of starvation. In yet other places from 1 to 12 
or 15 were counted. The total number of dead or dying pups actually 
counted was 106; there doubtless were many others. This condition 
was caused by a severe storm which occurred about the middle of 
June when the sea washed over the entire rookery, washing practically 
all the pups off the rocks and into the water. At that time the pups 
had not yet learned to swim and many were drowned outright. Others 
were probably so seriously injured they could not get back upon the 
rocks, and still others were washed ashore. The mothers do not 
appear to make any search for them and they crawl about and finally 
starve. 
It is quite evident that there is a large excess of adult bulls in the 
Ano Nuevo herd. The presence of these surplus bulls on the rookery 
results in severe fighting in which cows are injured and pups trampled 
to death. These surplus bulls should be killed and I have recom- 
mended that the Lighthouse Service kill 100 for their hides and oil. 
California Academy of Sciences, San Francisco, 
JOUBNAIi OP MAMMOIiOGY, VOL. 2 , NO. 1 
