Duration of stay ashore between trips to sea, 2 d or less. 



Size of average harem, 39. 



A female copulates only once a season. 



Bartholomew discussed in two other papers (Bartholomew 

 1953, 1959) other aspects of fur seal behavior. 



The ailment "spekkfinger" (seal finger, blubber finger) was 

 tentatively identified for the first time on the Pribilofs in 1951 

 when Rodahl and Jellison examined a hard, persistent swelling 

 on the finger of a temporary biologist. The ailment is uncom- 

 mon here and is disappearing from sealing areas over the world 

 as a result of improved sanitation. Svenkerud et al. (1951) pro- 

 posed to call the causative organism Corynobactehum phocae. 



"Salmonella enteritidis was isolated from blood and viscera 

 of 5 and 12 sick fur-seal pups . . . during the late summer of 



1951. Lice from one of the pups . . . also harbored S. enteri- 

 tidis. Salmonellosis may contribute significantly to mortality 

 of seal pups" wrote Jellison and Milner (1958:200). 



The Three-Nation Investigation of 1952 



Canada, Japan, and the United States agreed in 1952 to 

 launch a joint investigation of the distribution and food habits 

 of northern fur seals (Taylor et al. 1955:ii). The agreement 

 entered into force with respect to the United States and Japan 

 on 8 February, and with respect to Canada on 1 March. "The 

 Soviet Government declined [to join] but expressed an interest 

 in reestablishing international arrangements for the conserva- 

 tion of the seals" (Taylor et al. 1955:1). 



Why a new investigation? In 1896 the Jordan Commission 

 had been instructed "to conduct a scientific investigation . . . 

 of the present condition of the fur-seal herds on the Pribilof, 

 Commander, and Kurile islands" (U.S. Treasury Department 

 1896:5). That investigation and the treaty which followed in 

 1911 were conceived in desperation, in an effort to save the 

 seals from destruction. In 1952, though the security of the 

 seals was no longer threatened, the question of how best to uti- 

 lize the herds was faced by the North Pacific nations. Japan 

 had lost her sealing grounds on Robben Island and the Kuriles 

 to the U.S.S.R. in 1945. Intermingling of seal stocks of Asian 

 and North American origin, flatly denied in Jordan's time, 

 was now confirmed and was suspected of being important. 

 The people of Japan now numbered about 90 million and their 

 demand for food fish had risen greatly; the extent of predation 

 by seals on commercial fish was a correspondingly greater con- 

 cern. Pelagic sealing by Japanese during World War II had 

 reduced the Commander Island's herd, though to what new 

 level was unknown. These and other considerations lay behind 

 the joint investigation of 1952. 



"Two expeditions were, therefore, organized in February 



1952. One using six vessels operated off the coast of north- 

 eastern Japan from 19 February to 17 June; the other using 

 two vessels off the coast of North America. The latter investi- 

 gation was divided into two parts, the first operating off Cali- 

 fornia, Oregon, and Washington from 8 February to 30 April 

 and the second off Alaska from 4 June to 13 July. All three 

 Nations took part in the investigations off Japan, but Japan 

 was unable to participate in the investigations off North 

 America. The vessels hunted in waters important in pelagic- 

 sealing days. Seals were killed with shotguns and were ex- 

 amined by biologists with respect to presence or absence of a 

 tag or marks, the sex, age (determined by tooth-ridge counts), 



stomach contents, body length and weight, and length and 

 weight of fetus when present" (Taylor et al. 1955:2). Off 

 Japan, 2,329 seals were taken and off North America, 686. 

 The principal biologists in charge were: for Canada, Fred H. 

 C. Taylor (western expedition) and James I. Manzer (eastern); 

 for Japan, Fukizo Nagasaki; for the United States, Ford Wilke 

 (western) and Victor B. Scheffer (eastern). 



The investigation showed that three nations can jointly ex- 

 plore the biological bases for a treaty. It provided North 

 American biologists with a chance to develop a pelagic sealing 

 technique which they were later to use on many occasions. 

 Listed in order of importance, the main findings of the investi- 

 gation were as follows: 1) Seals of Pribilof origin composed 

 about 30% of the seals in waters off Japan in spring. (The 

 small sample taken in 1950 had indicated 10 to 25%.) 2) For 

 every age class, the pregnancy rate was higher in Asian than in 

 North American seals. Weighted to reduce sampling errors, 

 the overall rate for Asian seals was 80% ; for North American 

 seals 68% . A large part of the difference has been explained by 

 assuming that Asian seals mature earlier than do North Ameri- 

 can seals. This assumption was first published in 1964 (North 

 Pacific Fur Seal Commission 1964). "A comparison of sam- 

 ples from the eastern and western Pacific shows that female 

 groups of mixed origin in the western Pacific have a pregnancy 

 rate of approximately 50 percent in the fourth year, and those 

 mostly of Pribilof origin from the eastern Pacific have a rate 

 of approximately 50 percent in the fifth year" (North Pacific 

 Fur Seal Commission 1964:10). "A consistent difference of 

 one year in the age of reproductive maturity" was reiterated by 

 Pike et al. (1965 18 , p. 3). 3) Of the stomach contents of seals 

 taken off Japan, 3 1 % (by volume) represented species of some 

 commercial value; off North America, 36%. The main prey 

 species off Japan were lanternfishes and squids, 87% by 

 volume. Many kinds of fishes and squids were taken off North 

 America. Before 1952, almost nothing was known about the 

 food habits of seals south of Washington State. 4) In a com- 

 parison of skull measurements of 523 female seals 6 yr old or 

 older, it was concluded that seals from Asian waters and North 

 American waters are indistinguishable. Similar results were ob- 

 tained from a covariance study of body length against condy- 

 lobasal length. Wilke (1951) had anticipated this finding, 

 though on the basis of a smaller sample. 5) Pregnant females 

 were found to be longer in body and to have heavier teeth than 

 nonpregnant females of the same age. This phenomenon could 

 mean that larger (and stronger?) individuals tend to have a 

 higher pregnancy rate or it could mean that gestation brings 

 changes in the vertebral column and teeth. 6) Over 400 fetuses 

 were measured and weighed. On the basis of those taken in 

 North American waters, Chapman was able to estimate that 

 "the mean date of implantation is quite certainly in early 

 November" (Scheffer 1962:9). 



The joint investigation was carried out in 1952; the report 

 did not appear until 1955. As Kenyon wrote (in letter of 6 May 

 1954) "the area of disagreement among biologists of the three 

 countries is very small but because the report has been ex- 

 amined in the light of its political implications complete agree- 

 ment is difficult to reach." The release of the report in 1955 



"Pike, G. C, I. B. MacAskie, and A. Craig. 1965. Report on Canadian pe- 

 lagic fur seal research in 1964. Unpubl. rep., 16 p. Fish. Res. Board Can., Pac. 

 Biol. Stn. , Nanaimo, B.C. V9R 5K6 Can. 



38 



