582 



THE PUR SEALS OP THE PRIBILOP ISLANDS. 



There is a general backward movement from the bowlder beach to the flat above in 

 many places. On the 20th of July there was none of this and no seals were on the 

 slope of Hutchinson Hill. 



Comparing the condition of the rookery to-day as viewed from the hill, no differ- 

 ence can be detected over the conditions shown by the photograph of last year taken 

 in August. Professor Thompson therefore does not find much difference in the rookery. 

 It must be remembered, however, that the conditions of this part of the season do not 

 represent the rookery at all. Everything is confusion. Cows and pups are scattered 

 about, but everywhere more thinly. It is only where an actual count, as on Sea Lion 

 Neck, can be brought to bear that the difference can be shown, but in such places the 

 decrease is incontestable. It is only when the harem system is rigidly and compactly 

 adhered to as before the 15th of July that any adequate notion of the real condition 

 of the breeding grounds can be formed. Observations therefore at this time are made 

 at a decided disadvantage. 



On the patches at the western end of Vostochni the shrinkage is clearly marked 

 by comparison of the pups of this year with those present last season. I made a 

 count of live pups on the three southern patches, therefore it is possible to form a 

 reasonable judgment as to relative numbers. 



The large patch which extends back on the flat to the south of Hutchinson Hill 

 is black with pups and shows up plainly as the largest group of seals on this rookery. 



The dead pups on the flat under Hutchinson Hill are conspicuous and would bear 

 a fair relation to those of last year. They seem here, as at Tolstoi, to be chiefly the 

 victims of Uncinaria, and dissections show the worm to be present. 



AUGUST 7. 



Dr. Jordan and Professor Thompson went this morning to Zapadni to count dead 

 pups in the "death traps." Dr. Jordan reports that the gully which was covered 

 with stones has very few pups that seem to have been trampled. Most are apparently 

 the victims of Uncinaria or starvation. Of the 103 pups here, the following classifi- 

 cation of deaths is probably about correct: Starved, 15; Uncinaria, 65; trampled, 23. 



Last year's photograph shows 30 bodies worn bare. Doubtless as many as 45 of 

 the dead for that season were the result of trampling. The difference in appearance 

 of the bodies may, however, be due to the dry season. Last year there was more wet 

 weather, and doubtless the hair was worn off more quickly. 



The bowlders placed in the gully are not of the best kind. They are for the most 

 part small, such as could be carried up from the beach below. What is needed is the 

 larger angular bowlders. 



The following comparison of dead pup counts is of interest: 



