coincided with a growing, worldwide interest in marine mam- 

 mals, and the printing of 1,000 copies was soon exhausted. 



The U.S. biologists were busy with pelagic research in 1952 

 and had little time for studies on the Pribilofs. However, "Ap- 

 proximately 20,000 pups were tagged on St. Paul Island in 

 September. Data were obtained on animals tagged in previous 

 years, studies were resumed on the reproductive success of the 

 herd, and pup mortality was again recorded" (Thompson 

 1954:53). 



The biologists embalmed two seals and sent them to a bio- 

 logical supply house, which injected them and forwarded them 

 to Robert B. Chiasson, University of Arizona. Chiasson 

 (1955a) used them for a doctoral dissertation on the anatomy 

 of the seal. He used photographs of cross sections of another 

 seal. A 50-lb (23 kg) bachelor, frozen in 1952, was shipped to 

 Seattle and was cut with a band saw transversely into 14 2-in 

 (51 cm) discs (Fig. 12 top). In addition to his thesis, Chiasson 

 published two papers on seal dentition (Chiasson 1955b, 

 1957). 



Two seal pups were flown to the Seattle Zoo and a patch was 

 shorn from the silvery pelage of each on 24 November 1952 

 (Scheffer 1962:27). The regeneration of guard hair and under- 

 fur was noted at intervals until the captives died in 1953 and 

 1954. The experiment gave evidence on the duration of molt, 

 about 15 wk. Similar studies, though incomplete, were carried 

 out on four bachelor seals in 1954 and an adult and a subadult 

 female in 1957. The two pups captured on the Reef on 22 

 November 1952, shipped to Seattle in an aluminum dog crate, 

 and placed in the Seattle Zoo on 24 November, were the first 

 seals sent by air from the Pribilofs. 



The historical period which we have termed "establishment 

 of continuous research" closed in 1951-52 when a deadline was 

 drawn on the inclusion of new material in Kenyon et al. 

 (1954:4). In that report all useful evidence, old and new, on the 

 age and sex composition of the herd was reviewed. While bet- 

 ter evidence has since been obtained, the report is useful in 

 describing the population structure at the end of a 40- yr man- 

 agement regime in which only males were cropped. It is also 

 valuable in presenting the first life tables for male and female 

 seals based on known-age stock (Kenyon et al. 1954:38, 40). 



Studies in the Harvesting of Female Seals, 1953-57 



1953 



In the early 1950's, biologists concerned with the Pribilof 

 herd realized that it had ceased to grow, yet they were uncer- 

 tain what changes to recommend in harvesting practice to meet 

 the new situation. They agreed that release of population pres- 

 sure was called for. One thought was to increase the kill of 

 males by 6 or 7% per annum. Another thought, and the one 

 which was translated into action, called for the killing of 

 females. This proposal would both reduce the herd and correct 

 a possible (?) imbalance of sexes. Steady pressure from the 

 Japanese Government to reduce the herd was still being felt, as 

 it had been in 1941 when the United States cropped an extra 

 30,000 males. Furthermore, the joint investigation of 1952 had 

 shown that the pregnancy rate of Pribilof seals was low. If due 

 to a low ratio of males to females, some argued, then killing of 

 females would be desirable. 



The idea of killing "sacred cows" met resistance at first 

 from the Aleut inhabitants, steeped as they were in the tradi- 



Figure 12. — Top: Section through the head of a bachelor seal killed on 21 Au- 

 gust 1952. The carcass was frozen and cut into 2-in thick discs from snout to tail 

 for study of anatomy (photo by V. B. Scheffer). Bottom: Weighing seal pups on 

 St. Paul, 1962; Ford Wilke at left with pup (photo by R. D. Bauer). 



tions of the islands, and from Fouke Fur Company employees 

 who considered the subadult male Government Alaska Sealskin 

 a "gold standard" among furs. Females were first deliberately 

 killed in 1953 on an experimental basis. The most in a single 

 year, 47,413 were killed in 1957. After 1963 the kill was held to 

 a sustained annual level of about 18,000. 



Between 15 June and 4 September 1953, Wilke supervised 

 the experimental killing of 607 females on St. Paul Island 

 rookeries (Thompson 1955:61, 72). He and Robert Krear selec- 

 ted specimens at random, killed them by .22-rifle fire, and 

 dragged them to one side of the rookery. The kill was useful in 

 two ways: it showed that "harem raiding" is a poor way to 

 harvest females and it produced the first good evidence on age, 

 pregnancy rate, and body size among rookery females 

 throughout an entire sealing season. 



39 



