Figure 8. — Top: Tagging seal pups with "A" series monel lags on Polovina 

 Rookery, 24 September 1947, William H. Sholes, Jr., al right (photo by K. W. 

 kenyon). Bottom: Removing an adult from a pod of pups during tagging opera- 

 tion; St. Paul Island 1962 (photo by R. D. Bauer). 



rained 94.55 cows," an estimate which is surely two or three 

 times too high. 



On 4 October 1947, 173 seal pups were weighed. The means 

 were, for males 13.9 kg; for females, 12.0 kg. In a period of 3 

 mo, the pups had increased to approximately 2.5 limes their 

 newborn weight. 



1948 



The year 1948 marked an important breakthrough in popu- 

 lation studies. On the mornings of 14 and 15 July, in brilliant 

 weather, Scheffer and Kenyon flew over all of the Pribilof 

 rookeries in a twin-engine land plane equipped with an F-56 

 camera with an 8.5-in lens. They photographed the rookeries 

 from directly above, at elevations of 900 to 1,200 ft (275 to 365 

 m), and at a ground speed of about 90 mph (145 km/h). On 

 photo enlargements, Kenyon estimated the area occupied by 

 breeding animals and pups on each rookery. From counts 

 made on foot the following year of the number of pups on six 

 sample rookeries, he extrapolated to the total number of pups 

 born in 1949, or 580,000 (Kenyon et al. 1954:26-29). This esti- 

 mate resembled five others obtained by other means, ranging 



Figure 9. — Top: An attempt to photograph Polovina Rookery from 

 a captive-balloon camera 30 June 1947. Left to right: Raul Vaz Fer- 

 reira, Karl W. Kenyon, William H. Sholes, Jr., and Robert Z. 

 Brown (photo by V. B. Scheffer). Bottom: A scene from the first 

 comprehensive aerial photographs of the Pribilof rookeries: Polo- 

 vina Point, 15 July 1948. from 1,200 feel (photo by V. B. Scheffer 

 and K. W, Kenyon). 



32 



