34 SEAL LIFE ON THE PRIBILOF ISLANDS. 
NUMBER OF BREEDING FEMALFS ON THE ISLANDS. 
Upon the return of the Albatross to the Pribilof Islands on July 9, 
1895, a general examination of the rookeries was made. Some of the 
narrower breeding grounds were so thinly covered with seals that it 
seemed quite possible to count them. Accordingly, Mr. True and I 
began on Ketavie rookery and on the 9th and 10th sueceeded in taking 
a satisfactory census. The harems seemed full and well defined, no 
coalescing having begun, and they were therefore counted separately. 
This work was continued with Lagoon rookery and portions of Tolstoi, 
Lukannon, and Reef rookeries, where female seals were counted as fol- 
lows: Ketavie, 2,218; Lukannon, 1,940; Lagoon, 1,216; Tolstoi, 1,539; 
Reef, 566. The whole number counted was 7,479. 
Narrow places limited to the beach slope, like Lagoon rookery, were 
not difficult to count from a boat when the sea was smooth, while no 
trouble was encountered in doing the same with thin rookeries that 
could be viewed from low cliffs. The value of the data secured can not 
be overestimated, it being the first time that rookeries were found suf- 
ficiently reduced in the number of breeding females to admit of their 
numbers being determined with any degree of precision. Although 
these rookeries may not have quite reached their breeding height, they 
were so near to it that the corrections to be applied are unimportant. 
With a very fair set of figures for the extensive area thus examined, we 
are able to form a more accurate estimate of the number of breeding 
females on the Pribilof Islands than ever before. Adopting the scale 
of the rookery charts prepared by Mr. J. Stanley-Brown (264 feet to 1 
inch) we find the 7,479 seals counted to be distributed over 7.05 acres, 
making 1,061 seals to the acre. The remaining area occupied by seals 
has been computed at 54.47 acres, as based upon the rookery ground 
delineated on the charts for 1895. The result is a total of 65,239 breed- 
ing females for all the rookeries of the two islands. Some corrections 
might be applied for certain tracts on Reef, Tolstoi, and Northeast Point 
rookeries, where the seals always lie more or less massed, but I can not 
admit that there were between July 10 and 15 more than 75,000 breed- 
ing females present upon the islands. There is also a correction to be 
applied for a moderate number of females not on the rookeries at the 
time the breeding females were being counted. As the season was 
backward, and the females later than usual in arriving, their appearance 
was made en masse, so it is altogether probable that the number of 
absentees was not important. 
From the 10th to the 15th of July the rookeries were filled with 
females that had just brought forth their young. They had not notice- 
ably begun going to sea to feed, and at no other time were so many 
coming in heat. It is altogether unlikely that any very important 
number of females could have been away from the rookeries at a time 
when the females were still in excess of young. Mr. True found the 
percentage of young to be 62 on July 9, while on July 20 the young 
were everywhere in excess of females. Later in the season 50 per cent, 
at least, of the females were customarily absent from the rookeries. 
