ing females. Displaced bulls return stubbornly to their former 

 stand. Early arriving bulls stay on station for an average of 54 

 d. 



Two museum studies were published (King 1954; Sivertsen 

 1954) both of which illustrated and compared the skulls of 

 northern (Callorhinus) and southern (Arctocephalus) genera 

 of fur seals. 



1955 



In 1955, as in the previous year, female seals were killed for 

 size in regular male drives; 726 were taken (Thompson 

 1957:79). 



By 1955 the mass of research data including tag numbers 

 recovered from seals, body measurements, and information on 

 reproductive condition, had grown to the point where it called 

 for automatic data processing. Simple Keysort cards were used 

 at first, and in 1957 the IBM system was adopted. 



Tagged in 1955 were 49,870 pups, more than ever before 

 in 1 yr. The aim was to provide a better statistical base for 

 estimating the size of the Pribilof population and the degree of 

 intermingling of North American and Asian seals. Over an 

 8-yr period, 50,000 to 60,000 pups, representing 6 to 10% of 

 those bom, were tagged annually. The tagging slacked off in 

 1963 when evidence of tag-induced mortality was first 

 recognized. Approximately one-fifth of the tags applied in 

 1955 bore the serial letter "H", while four-fifths did not. 



"In an attempt to learn more about fur-seal feeding habits 

 and in particular to determine the effect of the seal popula- 

 tion on salmon feeding in or passing through waters in the 

 vicinity of the Pribilof Islands, the [biologists] in 1955 cap- 

 tured 204 fur seals at sea" (Thompson 1957:69-70). 



"In the stomachs of 1 17 fur seals . . . capelin was the domi- 

 nant food near the Aleutian Islands (52 per cent of total food 

 by volume) and was replaced offshore by squid and Alaska 

 pollack which there made up 47 per cent of total food by 

 volume. Salmon . . . and sand lance each appeared once" 

 (Wilke and Kenyon 1957:238). The seals were collected from 

 the Paragon, the first time that a halibut schooner had been 

 used for pelagic fur seal research. 



Fukuzo Nagasaki, of the Japanese Fisheries Agency, spent 6 

 wk in 1955 on St. Paul Island as an observer. He was later to 

 figure prominently in fur seal treaty meetings. 



1956 



From 28 November 1955 to 9 February 1957, the North 

 Pacific Fur Seal Conference alternately met and recessed. It 

 was successfully concluded, and in 1958 a four-nation research 

 program got under way. We will discuss this later. In the 

 meanwhile, during Conference discussions, the objective of 

 "maximum sustainable productivity" of the fur seal herds was 

 often discussed. In line with this objective, the United States 

 made an effort in 1956 to reduce the size of the Pribilof herd. 

 Females were deliberately killed, the length standards for 

 males were raised in order to provide more large animals, and 

 the killing season was extended into September. When the 

 season closed, 122,826 skins had been taken; the greatest 

 number harvested on land since the uncontrolled season of 

 1868. 



Details of the kill were given by Thompson and Erickson 

 (1960:69-70). Females were picked up from hauling grounds 



and rookeries throughout the season. Many seals were picked 

 up from grounds not ordinarily visited by the sealing gang; all 

 were killed, as usual, by club. "Harem raids" were again made 

 as in 1953, though on a much smaller scale. Hundreds of skins 

 were found to be stagy (molting) in August and September. 



The herd reduction program continued for 8 yr, through 

 1963. During this period the mean annual kill of females was 

 33,745 (4,315-47,413), while the mean annual number of 

 female skins saved for the market was 27,336 (4,296-47,423) 

 (Roppel et al. 1963:1, 1965b:l, 17; North Pacific Fur Seal 

 Commission 1964:85; Power 1964:11). That is, 81% of the 

 skins were used. 



During the 1956 kill, a record was kept for the first time of 

 the color of the whiskers (vibrissae) of females (Abegglen et al. 

 1956:82")- The purpose was to find an age index which could 

 quickly be spotted on the killing field. The 5-yr-old (entering 

 6th year) was found to exhibit the greatest variability in color; 

 most younger seals having black whiskers, most older ones 

 white. 



Scientific studies of the fur seal received new emphasis in 

 1956. Biologists Carl E. Abegglen and Alton Young Roppel 

 joined Wilke on the permanent research staff (Abegglen left in 

 1962). During the summer of 1956 the new laboratory on St. 

 Paul Island was occupied for the first time. On St. George 

 Island, a small laboratory was set up in the hospital, pup tag- 

 ging was initiated, and a summer biologist was first assigned to 

 the island. In winter, the Seattle research headquarters were 

 moved from Edmonds to Sand Point Naval Air Station. 

 "Biological research" attained the status of a separate chapter 

 in the annual report of the Pribilof fur seal business (Thomp- 

 son and Erickson 1960:72). The Bureau of Commercial 

 Fisheries was established as a component of the Fish and 

 Wildlife Service by a law which became effective on 6 

 November 1956 (70 Stat. 1119 (1956); U.S. Congress, House 

 1958:156-160). 



More tooth samples were collected in 1956 than ever before. 

 The sample quota was raised to 10% of males and 20% of 

 females. Biologists extracted, cleaned, and counted layers on 

 the right upper canine of about 7,000 males and 4,000 females. 

 By 1964 the sampling schedule for males had become routine, 

 as follows: "10 percent of a kill of 300 or more; 20 percent of 

 100 to 300; and 30 percent or more of 100 or fewer animals" 

 (Roppel etal. 1965a:3). 



The mortality of pups on land was high in 1956, partly 

 because lactating mothers were killed throughout the summer. 

 The count of dead pups by 26 August was 119,505 (including a 

 5% markup for pups overlooked). This is still the highest 

 count on record; it represents a mortality of 12% (North 

 Pacific Fur Seal Commission 1964, tables 12, 16). It is a con- 

 servative estimate, for pups continued to die after 26 August, 

 especially from starvation. 



About 46 man-days were spent in making the count on both 

 islands. To simplify the task in the future, 10 sample plots 

 representing about one-third of the pupping area on St. Paul 

 Island were delineated. Most of the plots were marked with 



"Abegglen, C. E., A. Y. Roppel, and F. Wilke. 1956. Alaska fur seal inves- 

 tigations, Pribilof Islands, Alaska. Report of field activities June-September 

 1956. Unpubl. rep , 145 p. Northwest and Alaska Fish. Cent., Natl. Mar. 

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

 Seattle, WA 981 15. 



41 



