
Figure 9. A sample count of living pups, Polovina 
rookery, 8 August 1949. Several thousand animals were rounded 
up; the adults were allowed to escape into the sea; the pups 
were driven in small numbers past two observers. Virtually 
no pups had taken to the water by this date (VBS 2683). 
The "rapid field estimate," whereby observers from a vantage 
point estimate the number of pups spread over the rookery before them, 
was tried in 1950 (fag. 10). This method has the great advantage of 
speed, for 5 to 10 thousand pups can be estimated in an hour. However, 
its success depends largely on the ability of the observer to estimate 
numbers, and it must be considered the least accurate of all methods. The 
best period for rapid field estimating is the first 10 days of August, when 
breeding activity has waned and before the pups have taken to the water. 
Dead—pup counts, abandoned in 1924, were resumed in 1941] by Wilke 
and Banner and again in 1949, 1950, and 1951. To obtain counts, the 
rookeries are visited in late August and dead pups are systematically 
counted (fig. 11). Earlier in the season, substantial numbers of pups 
destined to die are still alive; later many of those that died early in the 
season have disintegrated or washed away in the surf. The counting crew 
marks each carcass with a pinch of white plaster, simultaneously recording 
it on a mechanical hand tally. A crew of four can count approximately 2,000 
pup carcasses an hour. The count probably includes 95 percent of the actual 
number. 
-23- 
