Also in 1953 on St. Paul, 244 females were killed acciden- 

 tally during regular male kills; many of these were examined by 

 Wilke. (Females were not killed intentionally with males until 

 1954.) Comparisons given below illustrate some interesting re- 

 sults of Wilke's studies in 1953. 



In age composition the rookery sample of females clustered 

 around years 5, 6, and 7; the hauling ground sample around 

 years 4, 5, and 6. (The following figures are reworked from 

 Wilke 1953", table 10.) 



Number Percentage killed of each age 



Area killed 1 4 5 6 7 8 9 10 10+ 



Rookeries 551 3 6 14 15 10 8 8 6 30 



Hauling 

 grounds 164 3 16 49 19 5 2 1 5 



A similar relationship was confirmed many times in later 

 studies (North Pacific Fur Seal Commission 1964, table 9). 



With respect to pregnancy rates, Wilke (footnote 19, p. 23) 

 found that they average 89% for rookery seals and 67% for 

 hauling ground seals. A similar relationship was confirmed 

 later (Abegglen and Roppel 1959:78-79). He also noted that, 

 of 34 rookery 4-yr-olds, 23% were pregnant, while of 27 haul- 

 ing ground 4-yr-olds, only 7% were pregnant. We do not know 

 that the discrepancy has ever been explained. 



Wilke (footnote 19, table 8) observed a strong tendency for 

 females to arrive on the rookery in reverse order of age, the 

 oldest in early July and the youngest in late August. He also 

 noted (his table 2) that, within an age class, the heaviest 

 females tend to arrive earlier on the rookeries and hauling 

 grounds than do the lightest. The difference in weight between 

 the first and the last arriving groups was about 12%. (Excluded 

 from the samples were females obviously pregnant, i.e., with 

 near-term fetus.) 



In summer of 1953 Robert W. Rand, an observer for the 

 Union of South Africa, visited the Pribilofs (Rand 1955). He 

 was at that time engaged in studies of the biology and manage- 

 ment of the South African fur seal, Arctocephalus pusillus. 



The Fouke Fur Company had started before 1950 to experi- 

 ment with brine curing of sealskins to replace conventional dry 

 salting. By 1953, about two-thirds of all skins taken were brin- 

 ed, and within a year or so all were brined (Thompson 

 1955:61). In 1953, the Company experimented with a beaming 

 machine to replace blubbering by hand. It proved to have little 

 value because of the individual variation in thickness and 

 elasticity of skins. 



Scheffer transferred to headquarters 20 in Colorado in Sep- 

 tember 1953 and returned to the Marine Mammal Biological 

 Laboratory in July 1956. 



A seal exclosure was built on Vostochni Rookery in May 

 1953 to test whether hookworm larvae could move horizontal- 

 ly through soil. Exclosures of one kind or another are common 

 research tools of the wildlife biologist. The Vostochni struc- 

 ture may represent the first to be used for a marine mammal. 



While North American "aborigines" even today have a 

 treaty right to hunt fur seals pelagically, they have taken al- 

 most none since 1953. The high point in aboriginal sealing had 

 been reached in 1925, when the natives took 6,412 seals, repre- 

 senting 24% of the Pribilof harvest for that year (North 

 Pacific Fur Seal Commission 1964:31). 



1954 



Female seals, as well as males, from 41 to 45 in (1.0 to 1.1 m) 

 in length were deliberately killed in the drives of 1954. This was 

 done with the expectation of harvesting 5,000 females without 

 disturbing the rookeries. Plans fell short; only 658 females 

 were taken (Thompson 1956:53, 64). Evidently this number 

 represents about all that can be taken when seals in conven- 

 tional drives are killed for size but not for sex. 



O. W. Olsen had found that hookworm larvae survive over 

 winter in great numbers on the rookeries, even under ice. He 

 had found in laboratory studies that certain chemicals will kill 

 larvae in soil. In early summer of 1954, therefore, nematocides 

 (coal tar derivatives) were sprayed over 6.2 acres (2.5 ha) of 

 rookeries on St. Paul Island. None reduced the pup mortality 

 caused by uncinariasis (Kenyon 1954:4 21 ; Dixon 1955:23 22 ; 

 Thompson 1956:56). The count of dead pups continued to 

 rise. It was about 20,000 in 1941 on both islands and it reached 

 111,000 in 1954 and 120,000 in 1956. 



Dead seals older than pups were counted in 1954 on St. Paul 

 Island for the first time since the 1890's. The totals were 221 

 males and 423 females, or fewer than 1 % of the population. 



In the work plan for the summer of 1954 is a statement that 

 "specimens of diseased skin" were to be obtained for Cleve- 

 land J. White, of Chicago. In answer to an inquiry, Dr. White 

 replied (in letter of 3 July 1964): "According to my record, I 

 found an injurious fungus Trichophyton gypseum ( = T. men- 

 tagrophytes) on slides, both on microscopical examination 

 and, of course on Sabaraud's medium ... I did not publish the 

 findings." 



In the years between 1940 and 1955, before pup tagging 

 started on St. George Island, search was often made for tagged 

 seals on breeding grounds there. If it could be shown that seals 

 born on one island rarely take up breeding stations on another 

 island only 40 mi (66 km) away, then it could be argued that 

 few Pribilof seals "defect" to Asian islands. Up to the end of 

 1954, wrote Kenyon (footnote 21, p. 26), only one St. Paul 

 seal, a bull, had been seen on a St. George rookery. 



Kenyon studied the wandering of pups on land in late sum- 

 mer. Ten thousand had been tagged on 7-10 September 1954. 

 On 20-21 September, 236 tagged pups were rounded up on five 

 rookeries; only 14 pups (or 6%) were found to have strayed 

 from home. 



He marked 30 bulls with white paint in 1954 and observed 

 their territorial movements (Kenyon 1960). He found that 

 bulls tend to choose their territories in early summer without 

 regard to locations most likely to be selected by the first arriv- 



"Wilke, F. 1953. Alaska fur seal investigations, Pribilof Islands, Alaska, sum- 

 mer of 1953. Unpubl. rep., 34 p. Northwest and Alaska Fish. Cent., Natl. Mar. 

 Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., 

 Seattle, WA 98115. 



30 Cooperative Wildlife Research Unit, U.S. Fish and Wildlife Service, Col- 

 orado State University, Ft. Collins, CO 80521. 



''Kenyon, K. W. 1954. Alaska fur seal investigations, Pribilof Islands, sum- 

 mer of 1954. Unpubl. rep., 48 p. Northwest and Alaska Fish. Cent., Natl. Mar. 

 Mammal Lab., Natl. Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., 

 Seattle, WA 981 15. 



"Dixon, C. F. 1955. Report on the fourth summer of investigations on hook- 

 worms, Uncinaria lucasi Stiles, 1901, and hookworm disease of fur seals, Callo- 

 rhinus ursinus Linn., on the Pribilof Islands, Alaska, from May 31 to September 

 7, 1954. Unpubl. rep., 36 p. U.S. Fish Wildl. Serv., Washington, D.C. 



40 



