A skeleton of a fur seal was prepared in 1963 for use in the 

 Marine Mammal Biological Laboratory. A rough-trimmed 

 carcass was placed in Village Lagoon, St. Paul Island. Within 

 a few days, large marine amphipods which swarm in these 

 waters had cleaned off all but finer shreds of connective tissue. 



The "seal-fish" Balhylagus spp. was identified in 92 seal 

 stomachs collected in the Bering Sea in 1963 (Fiscus et al. 

 1964:13, 14). It had last been reported in seals in the 1890's. 



Hiroshi Kajimura joined the Laboratory in November 1963 

 to assist in pelagic research. 



Jones (1963) summarized reports that fur seals in winter oc- 

 casionally cross the Alaska Peninsula. They may travel up to 3 

 mi (5 km) on land. 



Yearlings were first tagged in 1961; tagged individuals were 

 looked for and recovered on the killing fields in 1962. In 1963, 

 the search for tagged yearlings was extended to the rookeries; 

 73 were found on St. Paul Island between 17 September and 17 

 October (Roppel et al. 1965b:l8-19). When it was first being 

 developed in 1963 the "yearling survey" required 2 d; later, 

 when it was concentrated on nine sample plots, it required only 

 7 h. In 1964, a total of 47 tagged yearlings were counted 

 (Roppel et al. 1965a: 11). 



During pelagic investigations in the Bering Sea in midsum- 

 mer 1963, a special effort was made to collect and examine 

 paired seals for evidence of mating at sea (Fiscus et al. 1965:7). 

 Ten females from pairs were collected this year and seven in 

 1964 (Fiscus and Kajimura 1965:12). Sixteen of the 17 females 

 had recently ovulated or were about to ovulate. One of the 

 males persisted in staying near the dead body of the female. 

 These observations suggested, but did not prove, that copula- 

 tion may occur at sea. 



Keyes began a study in 1963 of artificial diets capable of 

 maintaining seal pups in captivity. (The problem is aggravating 

 and of long standing. Zoo keepers over the world have dif- 

 ficulty in weaning young seals.) Earlier efforts by Olsen and 

 Lyons had been unsuccessful. The 1963 experiment, utilizing 

 20 captive pups, was also unsuccessful; none of the pups gain- 

 ed weight, though one lived for 25 d (Keyes footnote 47, p. 

 2-21). 



He isolated three organisms not previously known from the 

 fur seal; Proteus mirabilis, Aerobacler aerogenes, and "Strep- 

 tococcus sp. (probably enterococcus)" (Keyes footnote 47, p. 

 27). He found microfilariae in the blood of 35 of 40 bachelors, 

 a suprisingly high incidence (Keyes footnote 47, p. 44). 



He obtained good samples of seal milk which were analyzed 

 by U. S. Ashworth. He reported on certain features of seal 

 blood, heart rate, respiration rate, body temperature, stomach 

 capacity, and speed of mammary regression (Keyes footnote 

 47, p. 56-57). In the field of pharmacology, he tested tran- 

 quilizing and anesthethizing drugs, anthelmintics, and milk- 

 releasing drugs. He embalmed and injected a bachelor seal for 

 anatomical study (Keyes footnote 47, p. 65). 



One or more Fish and Wildlife Service biologists had been 

 studying the fur seal herd almost continuously since 1940. In 

 December 1963 the Service began to publish their research 

 findings in two series of annual progress reports, one dealing 

 with Pribilof studies and one with pelagic studies (Roppel et al. 

 1963; Fiscus et al. 1964). The publications were retroactive to 

 the field season of 1962. 



1964 



In a critical study of fur seal population estimates. Chapman 

 (1964) called attention to two basic unresolved questions. Why 

 does the estimated number of pups-at-time-of-tagging vary 

 widely from year to year — as much as 29%? Is the survival 

 rate of females from birth to age 3 actually, or only apparent- 

 ly, greater than that of males? In answer to the first, he con- 

 cluded that variation is mainly a result of tag-induced mortal- 

 ity. Tagged pups are more sensitive to environmental stress 

 than are their untagged classmates; and since the tagged pups 

 are the source of estimates, they unduly affect the estimates. In 

 answer to the second question. Chapman used elaborate rea- 

 soning (which we will not detail here) to deduce that about 125 

 females survive to age 3 for every 100 males. 



Allison M. Craig visited St. Paul Island in August to con- 

 duct experiments on the effects of pituitary extracts of seals on 

 the reproductive organs of captive female seal pups. She was 

 the first woman to engage in scientific studies of the fur seals 

 on the Pribilof Islands. Her important paper on fur seal repro- 

 duction appeared the same year (Craig 1964). It presented new 

 evidence that: 1) Follicular activity is not resumed until 6 mo 

 after parturition in the ovary of the parturient horn. 2) First 

 ovulation in the nulliparous female occurs in late August or 

 September, 1.5-2 mo later than subsequent ovulations. 3) The 

 percentage of 4-yr-olds ovulating is greater than the percentage 

 of 5-yr-olds pregnant, suggesting a scarcity of breeding males 

 when the young females first ovulate. (This theory is uncon- 

 firmed.) 4) After double ovulation, one blastocyst may mi- 

 grate to the opposite horn, resulting in twins. 



Craig coined the term "missed pregnancy" to describe 

 failure of the reproductive apparatus (for any reason) between 

 ovulation and implantation. 



For 8 d, beginning 17 July 1964, during the kills on St. Paul 

 Island, the minimum length limit was removed so that all 2-yr 

 males appearing in drives would be taken (Roppel et al. 

 1965a:3). The immediate goal was to obtain a measure or index 

 of the survival of the class of 1962; the final goal was to 

 establish the relationship between the strength of any 2-yr class 

 and the return of its survivors as 3-yr-olds the following year. 

 A sample of 2-yr males was again taken in 1965, though only 

 during 5 d, 22-26 July. Sampling was slated to be repeated in 

 future years. 



As 2-yr males were being sampled, they were also being 

 measured. Never before had body-length measurements been 

 obtained from a random sample of hauling-ground 2-yr males, 

 unharmed by brand or tag. From the length frequency dis- 

 tribution of individuals taken during the sampling period in 

 1964 and 1965 it was possible to estimate the numbers of 2-yr 

 males that would have been taken, had the entire sealing 

 season been a sampling period. 



From time to time since the 1890's, live pups have been 

 counted on sample rookeries by either of the methods known 

 as "running the gantlet" or "reconnaissance." An annual 

 count was started at Kitovi Amphitheater in 1959, extended to 

 Little Polovina in 1963, and to Zapadni Reef and part of 

 Morjovi in 1964 (Roppel et al. 1965a: 19). 



The numbers of pups on uncounted areas have been esti- 

 mated by extrapolation from counted ones through use of the 

 "average harem" concept. (We have mentioned another, and 

 distinct, series of pup counts designed to reveal the percentage 

 of sheared among unsheared individuals.) 



52 



