As of 10 August 1949, the estimated number of living and dead 
pups was, in round numbers, 470,000 (table 9). (As a practical consider- 
ation this is equivalent to the number of pups born.) In terms of 
breeding cows the estimate is not far from the "total of 480,000 cows, 
a number scarcely exceeded in the history of the herd"' to which Osgood, 
Preble, and Parker referred (1915, p. 50). They postulated an annual 
replacement of 2,000 bulls, a total harem—bull class of 12,000, and an 
average harem of 40. With the facts available to them in 1914, when the 
herd was only one-fifth its present size, it is interesting that their 
predictions were so close to our present understanding of herd size. 

Figure 11. A count of dead pups, Vostochni rookery, 
11 August 1948. The biologists counted 21,600 dead pups on 
1-1/2 miles of shoreline here. White plaster, used to mark 
each carcass as it is counted, is visible on some of the 
dead pups. Hookworm disease is the immediate cause of death 
of most pups dying on land; an estimated 1 percent die of 
starvation. Crowding may account for the increased mortality 
rate among pups in recent years (VBS 2441). 
Estimate of the number of pups born in 1949 from sample counts 
used with ground-area measurements.-—-At the height of the breeding season 
in July, individual seals and family groups, or harems, are spaced rather 
uniformly on the rookeries. The breeding areas are well defined and rather 
uniformly occupied from year to year. Noting this, Charles Bryant in 1869 
attempted to estimate the number of am by mapping and crudely measuring 
