On 20 December 1950, the Fish and Wildlife Service con- 

 tracted with the University of Washington for the part-time 

 statistical advice of Douglas G. Chapman. Essentially the same 

 contract has been kept alive down to the present. 



The second Alaska fur seal bred and born in captivity saw 

 light in the San Diego Zoo on 20 July 1950. It was a male and 

 on 22 July weighed 9!4 lb (4.2 kg). It died of an unknown ail- 

 ment on 7 September 1950, at which time it weighed about 28 

 lb (12.7 kg). 



After the breakup of the Fur Seal Treaty in 1941 , the United 

 States and Canada entered into an executive agreement in 1942 

 to regulate sealing in the northeastern Pacific; this agreement 

 was renewed in 1947. By public statement in Tokyo on 12 June 

 1951, Japan agreed to prohibit pelagic sealing, pending the 

 conclusion of a new fur seal treaty (Anonymous 1951). 



By 1951, plans were being laid by the United States to draw 

 the four nations of the North Pacific again into a fur seal con- 

 vention. In a memo of 16 April 1951, William C. Herrington, 

 of the State Department, proposed an international study of 

 the migration, numbers, and food habits of fur seals. The 

 study got under way in the next year, 1952, when the peace 

 treaty with Japan was also signed. 



1951 



While the need was recognized in 1951 for renewed studies 

 of the Pribilof herd, funds were short and the Fish and Wild- 

 life Service conducted only a modest program of research that 

 year. The old, unsatisfactory laboratory on St. Paul Island was 

 still in use. Its facilities were overcrowded in summer by five 

 collaborators and visiting scientists, namely: George A. Bar- 

 tholomew (University of California at Los Angeles), who stud- 

 ied seal behavior; O. Wilford Olsen (Colorado Agricultural 

 and Mechanical College), who launched the first of an annual 

 series of hookworm studies; Raymond Aretas (Office de la 

 Recherche Scientifique d'Outre-mer, Laboratoire des Peches 

 et Productions Coloniales, Museum d'Histoire Naturelle, 

 Paris), an observer; Karre Rodahl (Arctic Aeromedical Labo- 

 ratory, Ladd Air Force Base, Fairbanks), who studied infec- 

 tion known as "spekkfinger"; and William L. Jellison (U.S. 

 Public Health Service), who was interested in parasites and 

 diseases of wild animals and man (Bartholomew and Hoel 

 1953; Olsen 1958; Aretas 1951; Rodahl 1952, 1953; Jellison 

 195 1", 1952; Jellison and Milner 1958). 



Wilke had served in the old Food Habits Laboratory of the 

 Fish and Wildlife Service. During the summer of 1951 on the 

 Pribilofs he noted fur seal "spewings" on the beaches, as well 

 as numerous fish otoliths (ear bones) which had resisted 

 weathering of the spewings. He and Kenyon collected otoliths 

 and found that all were from codlike fishes up to a foot long: 

 Theragra chalcogramma, Gadus macrocephalus, Microgadus 

 proximus, Boreogadus saida, and Eleginus gracilis. He tenta- 

 tively concluded that "fur seals depend to a large degree on 

 small fishes of the family Gadidae during their stay in the Ber- 

 ing Sea" (Wilke and Kenyon 1952:397). 



In 1954, Kenyon pursued further the idea that information 

 on food habits might be obtained on land. Little attention had 



been given to the stomachs of seals on land, for it was known 

 that they were usually empty. Kenyon had the sealers slit open 

 the stomachs of 50,239 seals and he found that about 1 in 

 1,500 contained appreciable food remains. The remains were 

 94% by volume Pacific sandfish, Trichodon trichodon, and 

 6% sturgeon poacher, Agonus acipenserinus. Neither species 

 had previously been recorded as fur seal food (Kenyon 1956). 



Funds being short, only 1 ,000 seal pups were tagged in 1951 . 

 On 100 of the pups, half of the left ear was clipped off. (Ear 

 clipping had last been tried in 1924.) No clipped seals were seen 

 later, probably because the sample was too small. 



In 1951 for the first time a plot of breeding ground was 

 marked off as a counting area for estimating pup mortality 

 during summer. The rate started at zero on the 1st of July, 

 reached a peak in late July, and dropped to zero in mid- 

 August. 



In O. W. Olsen's first summer on the islands, he examined 

 722 animals, mostly fur seals and sea lions (O. W. Olsen 

 1951"). He found hookworms in the intestines of many fur 

 seal pups, but in no older seals, though he examined several 

 hundred 2-yr-olds and older. The over-winter reservoir of the 

 hookworm was to remain a mystery until 1961 . Olsen or one of 

 his graduate students, Carl F. Dixon, Dale R. Masters, or 

 Eugene T. Lyons, was on the Pribilofs each summer from 1951 

 to 1962, with the exception of the 3-yr period 1956-58. 



The biologists and G. A. Bartholomew collaborated in tak- 

 ing the temperature of 322 seals. "The bulls and cows at rest 

 have a mean deep body temperature of 37.7°C [99.9°F]. Pups 

 have a mean rectal temperature of 38.2°C [100.8°F]. Body 

 temperatures may [under stress] rise as high as 43.9°C 

 [111.0°F], but temperatures higher than 41.5 [106. 7°F] are 

 found only in animals incapacitated by heat exhaustion" (Bar- 

 tholomew and Wilke 1956:336). 



Wilke collected a sample of fur seal milk in 1951 for analysis 

 and found that it was 46.0% fat (Wilke 1958). Two samples 

 were taken from a female in estrus, about 6 d after parturition. 



On 19 July 1951, Kenyon photographed several breeding 

 and hauling grounds from a U.S. Navy helicopter at altitudes 

 between 20 and 300 ft (6 and 90 m). The flight was on an over- 

 cast day between 2:15 and 3:00 p.m. The aircraft threw the 

 seals into a panic and, though the photographs were reason- 

 ably sharp, Kenyon concluded that the method was unsatis- 

 factory. 



We have mentioned Bartholomew's 41-d study of seal be- 

 havior in 1951 at Kitovi Amphitheater. It is historically impor- 

 tant as the first attempt to use statistical methods for deter- 

 mining the time relationships of reproduction in the fur seal. 

 Important results (mean parameters) are listed below (Bar- 

 tholomew and Hoel 1953): 



Mean date of the pupping season (half of the pups born), 16 



July. 

 From arrival of the female to parturition, 2 d. 

 From parturition to estrus, 6 d. 

 Departure for sea after onset of estrus, 1 d. 

 Duration of first trip to sea, 5 d. 



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

 Seattle, WA 981 15. 



"Jellison, W. L. 1951. Sealer's finger or speckfinger. Unpubl. manuscr., 4 p. 

 I ".S. Public Health Service, Rocky Mountain Laboratory, Hamilton, MO 54644. 



"Olsen, O. W. 1951. Report on investigations of hookworms, Uncinaria 

 lucasi Stiles, 1901, and hookworm disease of fur seals, Callorhinus ursipus, 

 on the Pribilof Islands, Alaska from July 7 to September 2, 1951. With sup- 

 plementary report by W. L. Jellison. Unpubl. rep., 98 p. Colorado State Univer- 

 sity and U.S. Fish and Wildl. Serv., Denver, CO 80521. 



37 



