the average were microbial infection and 

 traunna in 1964, multiple hemorrhage-perinatal 

 complex in 1967, and malnutrition and micro- 

 bial infection in 1968. 



We conclude that observed fluctuations in 

 mortality are probably influenced by changes 

 in the incidence of one or two causes of death 

 rather than a general increase or decrease in 

 the incidence of all. 



DEAD SEALS COUNTED THAT WERE OLDER 

 THAN PUPS 



All beaches of St. Paul and St. George Islands 

 are now routinely examined each year for dead 

 fur seals older than pups. Seals of both sexes 

 are counted, and canine teeth are collected from 

 each for studies of age and mortality. Table 7 

 shows the number of dead animals counted in 

 1965-68, and table 8 the age composition of 

 dead males age 6 and older in 1965-68. 



Table 7. — Dead seals counted that were older than pups, 

 Prlbllof Islands, Alaska, 1965-68 



Table 8. — Age composition of dead male seals, 

 age 6 and older, Pribilof Islands, Alaska, 

 1965-68 



LIVING ADULT MALE SEALS COUNTED 



In 1968, the adult males were counted on 

 all rookeries in June and July on St, George 

 Island (tables A- 17 and A- 18) and in June on 

 St. Paul Island and Sea Lion Rock (table A- 19). 

 Since 1966, the number of adult males on 

 St. Paul Island in July has been estimated from 

 sample counts. For example, adult males were 

 counted only on Reef, Zapadni Reef, Vostochni, 

 and Morjovi Rookeries in July 1968 (table 

 A-20). We then extrapolated these counts to 

 produce estimated totals of 6,176 harem and 

 3,100 idle males for St. Paul Island, under the 

 assumption that decreases on the sample rook- 

 eries from 1966 (the last year in which a total 

 count of adult males was obtained for St. Paul 

 Island in July) to 1968 (table A-Zl) represented 

 similar changes on all rookeries during this 

 period. 



The total number of adult males counted on 

 the Pribilof Islands in July has decreased 

 annually since 1961 (table A-2.Z). If we con- 

 sider only the counts obtained in 1962 and 

 later, which were made by the same individual, 

 the number of harem (7,924) and idle (4,383) 

 males counted in 1968 represents 63 and 37 



Age 



1965 



1966 



1967 



1968 



-Number- 



177 



109 



6 



5 



8 



13 



15 



17 



17 



15 



5 



8 



2 



115 



Age could not be determined for five seals 

 older than 10 years because their teeth were 

 broken. 



percent, respectively, of the number counted in 

 1962. 



The rookeries on the Pribilof Islands were 

 divided into sections containing about 100 class 

 3 males in July. The sections on St. Paul Island 

 were established in 1966 from counts of class 

 3 males in 1965, whereas the sections on 

 St. George Island were established in 1968 

 from the number of class 3 males counted in 

 July of that year. Sections were not yet marked 

 on St. George Island when the adult males were 

 counted there in June 1968. 



REPRODUCTIVE CONDITION OF FEMALE 

 SEALS 



Age and reproductive condition were de- 

 termined for 2,473 females killed on St. Paul 

 Island from 26 June to 16 August 1968 (table 

 9). The genital tracts of these females were 

 examined for evidence of parturition in 1968, 

 and ages were obtainedfrom rightupper canine 

 teeth. Whole teeth from females age 6 and 

 younger and sectioned teeth from females age 

 7 and older were used. 



The pregnancy rates (table 9) do not repre- 

 sent the total population of females because the 

 aninnals killed were taken from hauling grounds 

 where the pregnancy rate is lower than on the 

 rookeries. Data collected in most years from 

 rookeries and hauling grounds cannot be sep- 

 arated, although comparisons of pregnancy 

 rates of females from these areas are available 

 for 1956-58 and 1968 (table 10). 



11 



