only three bulls were seen. They were com- 

 monly seen again during August and into early 

 September, but none were seen after 13 Sep- 

 tember. In early October a vessel sailed 

 across the Gulf of Alaska on a course similar 

 to that sailed in May. No bulls were sighted 

 although weather conditions were favorable. 



Tag Recoveries 



Fifty seals (3.4 percent of all seals col- 

 lected in 1962) bore tags (table 6). 



A female seal tagged in the U.S.S.R, in 

 1960 and collected on 4 October in Unimak 

 Pass is the first seal with a Soviet tag col- 

 lected in waters off the American coast. 



Size and Reproductive Condition 



Size. — Lengths and weights of the seals 

 collected are given in tables 7 through 14. 

 Taylor, Fujinaga, and Wilke (1955) first re- 

 corded that pregnant fur seals are slightly 

 longer than nonpregnant seals of the same 

 age. This difference, which is most noticeable 

 in seals under 10 years of age, has been ob- 

 served in the pelagic collections from 1958 

 through 1962. In 1962, the mean lengths of 

 548 post partum females were compared with 

 mean lengths of 282 pregnant and 513 non- 

 pregnant females (fig. 11). The plotted lengths 

 show the difference between the pregnant and 

 nonpregnant females. The growth curve for 



post partum females closely agrees with the 

 curve for nonpregnant females, rather than 

 with that for pregnant females as would be 

 expected. Measurement errors may account 

 for this result, otherwise no valid explanation 

 can be given. 



Tables 15 and 16 give the lengths and weights 

 of fetuses collected from 1958 through 1962. 

 The average weight and length of fetuses by 

 10-day periods are plotted in figures 12 and 

 13. Of 285 fetuses collected in 1962, 15 were 

 taken in May, 204 in June, 65 in July, and 1 in 

 August. The last, a normal full-term female 

 fetus weighing 5.3 kg. was collected on 11 

 August from a 21-year-old female. 



Pregnancy rate. — The pregnancy rate of 

 seals collected from 1958 through 1962 is 

 shown in table 17. In 3- and 4-year-old 

 females, the variation in pregnancy rate from 

 year to year could be a result of sampling. 

 In part this may be due to difference of popu- 

 lation make up between the collection areas. 

 It cannot be clearly shown where age of 

 maturation of young females accounts for 

 variation in the pregnancy rate. In the older 

 year classes, variation in pregnancy rates 

 in part may be caused by insufficient sample 

 sizes and variation in the onset of senility. 



By combining all females, ages 6 through 

 26, into one group (the sexually mature popu- 

 lation) the pregnancy rate is found to be 



Table 6. --Pelagic tag recoveries of fur seals collected by U. S. research 

 vessels off Alaska in 1962 



j_/ Includes one Soviet tagged seal (MOSCOW "BHNPO"-C 29850). 



2/ Includes H numbers 1-10.000. no series letter numbers 10,001-50,000. 



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