96 THE FUR SEALS OF THE PRIBILOF ISLANDS. 
all this the total results as here given are close enough to the actual conditions for all 
practical purposes. The total of 157,405 breeding seals means between 150,000 and 
160,000. No closer accuracy is claimed for the figures, and noneis needed. The margin 
of error can not be greater than this. 
THE CENSUS OF 1897. 
In making the census of 1897 no such difficulty as that encountered in 1896 was 
met with. From the start we had a clear idea of the problem and were guided by the 
experience obtained in the work of the former season. The first thing to be done was 
to make a full enumeration of the breeding harems on all the rookeries at the height 
of the season. The remaining step was to obtain an average size of harem by making 
a count of live pups on some typical rookery space. Accordingly between the period 
of July 13 and 20 the count of harems was made. For purposes of comparison the 
cows actually present on rookeries counted last year were recounted this year on 
the same dates. . 
THE COUNT OF PUPS IN 1897. 
The count of pups was made between the 28th of July and the 3d of August. 
A comparison of the number of pups with the number of cows counted showed clearly 
the inadequacy of our correction of 75 per cent for absent cows in the original census 
of 1896. These counts of cows and pups for 1897 are as follows: 
Comparison of counts of cows and pups, 1897. 
Cows 
Rookery. present. Pups 
Kit Whose aiziaie ponds netdiaceadeSas de aes aleee tice nade ns samara! - 2,436 5, 289 
Lagoon ......-..---.-- wee 1,319 2, 598 
eae Reef........- rer Sia aia 1, 049 3, 041 
Polovina (cliffs) mise TAT 2, 200 
ALU SUN oscec.cnis meesteeasesiesnssesees ecsiecasaeceseeed eeeecie 470 736 
Little Hast: «scccccccssaceccesieesectssseemisccn seemeeeerecede 497 1,190 
MOtAl scices ahocciesicdsaw skichsaswhaisepenivigeelaisewacscae 6, 518 15, 054 
THE PROPORTION OF COWS TO PUPS. 
These counts seem to show that the cows belonging to any rookery for the season 
are about 2.61 times as numerous as the cows found present at any one time in the 
height of the season. But an examination of the figures for Zapadni Reef and for 
Polovina cliffs indicates an abnormal condition of things on these rookeries. In both 
cases the pups outnumber the cows nearly three to one. It would seem likely that 
the weather or some other cause had on these rookeries produced an unusual effect 
for the day when the counts were made. 
In view of this apparently abnormal condition in part of the rookeries counted, 
it has been thought best in the census of 1897 to waive the general average results 
and take the simple conditions of Kitovi rookery as again typical. We find from a 
comparison of this rookery for the two seasons that its condition is apparently 
normal. In 1896 there were 182 harems, 3,152 cows present on July 13, in the 
height of the season, and 6,049 pups in August; in 1897 there were 179 harems, 2,436 
cows actually present on the same date, and 5,289 pups in August. 
