1963. Seals were feeding slightly closer to the 

 Pribilof Islands than in 1963, however. 



Surface water temperature in the Bering Sea 

 ranged from 7° to 10° C. when the collections 

 were made. 



Relative abundance of seals, and size of 

 groups. --The number and relative abundance 

 of seals seen and collected, by 10-day periods, 

 are shown in appendix tables 1 and 2. Fewer 

 seals were seen and collected off California 

 during April and May than in January to March 

 of 1958, 1959, or 1961.3 Numbers of seals 

 seen and collected in the Bering Sea were 

 comparable to 1962 (Fiscus, Baines, and Wilke, 

 1964) and 1963 (Fiscus, Baines, and Kajimura, 

 1965). 



The number of seals per group was similar 

 to that in previous years (appendix table 3). 

 About 88 percent of the seals (96 percent in the 

 Bering Sea, considered separately) were in 

 groups of three or less. The largest group 

 sighted off California contained 10 seals, and 

 in the Bering Sea, 6. 



Of the 2,864 seals sighted in 1964, 883 were 

 collected; 97 were wounded and lost, and 68 

 were killed and lost. 



Distribution by Age and Sex 



The age and sex of seals collected in 1964, 

 by month and area, are presented in table 1. 



In the spring off California, 305 seals were 

 collected. More males (20) were collected 

 there in 1964 than in 1958, 1959, or 1961.-^ A 

 5-year-old male from the Farallon grounds 

 was the oldest male collected to date off 

 California. 



Of 38 seals (5 males and 33 females) col- 

 lected off Oregon and Washington, 66 percent 

 were age 4 or younger. 



Males form a small segment of the Cali- 

 fornia fur seal population and appear later in 

 the spring than the females (table 2). The 

 females begin to arrive in December and by 

 January are present in appreciable numbers. 

 Young females (ages 1-4) are present from 

 January through May but are relatively more 

 abundant in April and May, when young seals 

 are still moving southward or shoreward and 

 mature females are migrating toward the 

 breeding grounds. 



In general, summer distribution of fur seals 

 in Bering Sea was sinnilar to that observed 

 in previous years. Mature females appeared 

 to be scarcer in sector 1, zone 7 in July than 

 in other years, but were dominant in samples 

 taken during 2 days in early September. 

 Although samples were small, the age com- 

 position of young males was different than in 

 1963. In 1963, 30.7 percent of the males were 

 2 years old and 23.4 percent were 3 years old 



^See footnote 2, p. 2. 

 See footnote 2, p. 2. 



(Fiscus, Baines, and Kajimura, 1965); in 1964 

 the percentages were 23.4 and 44.8. 



Pairing at Sea 



Special efforts were made again in 1964 to 

 collect nnale and female pairs in Bering Sea 

 and to explore further the possibility that 

 seals mate at sea. Four pairs, and the females 

 from three other pairs, were collected. 



Of the seven females, four were nuUiparous 

 (one with ovarian follicles less than 5 mm. in 

 diameter, 6 years old; two with ovarian 

 follicles more than 5 mm. in diameter, 5 and 

 7 years old; and one with ovarian follicle 

 recently ruptured, 4 years old), and three were 

 multiparous (two post partum, age 9 and 11; 

 and one nonpregnant, age 11; a corpus luteum 

 was forming in one ovary of each). Three of 

 the males were 5 years old, and one was 9 

 years. 



All males were mature enough to have active 

 sperm in their testes (no samples of testicular 

 tissue were saved for verification, however); 

 only one of the females appeared to be in 

 estrus. Mating at sea was not proved or dis- 

 proved. 



Tag Recoveries 



Tag recoveries for 1964 are shown in table 

 3. The proportion of tagged seals in pelagic 

 collections has increased progressively from 

 0.9 percent in 1958 to 4.9 percent in 1964. 

 One 4-year-old female fur seal tagged on 

 Bering Island by the U.S.S.R. was collected 

 on 28 August 1964, about 60 miles northeast 

 of St. Paul Island in the Bering Sea (lat. 57° 

 41' N., long. 168° 26' W.). This is the second 

 Soviet-tagged seal collected by the United 

 States off the American coast since the cur- 

 rent pelagic research began in 1958 (the first 

 was collected near Unimak Pass, Alaska, in 

 1962). 



Size and Reproductive Condition 



Size . --Lengths and weights are given for 

 pregnant, post partum, and nonpregnant 

 females collected in 1964 in appendix tables 

 4-9, and for males in appendixtables 10 and 11. 

 The mean lengths and weights of male and 

 female fetuses collected in 1964 are shown by 

 10-day periods in appendix tables 12 and 13. 



Reproductive condition. - -Reproductive con- 

 dition of females collected in 1964 is shown 

 in appendix tables 14-17, by area, age, and 

 month. NuUiparous females formed about 

 40 percent of the catch of females in April 

 and May off California. 



The size and condition of graafian follicles 

 in ovaries of females collected in July, August, 



