Collection of canine teeth, recovery of tags, 

 and recording of checkmarks were done nnid- 

 way between the sprinklers and the grinder. 

 Standing on a platform 3 feet high, one man 

 used a hack saw to remove the snouts just 

 anterior to the eyes (fig. 5). From this posi- 

 tion, the snouts passed the worker at eye level. 

 Twenty percent or more of the seals were 

 sampled daily for right upper canine teeth by 

 .taking the snouts from carcasses 1 and 2, 11 

 and 12, 21 and 22, etc., until all seals killed 

 that day had passed. Another man examined 

 left front flippers for tags and checkmarks as 

 he walked in a direction opposing that of the 

 moving line of carcasses (fig. 6). When he 

 reached the sprinklers, the worker inserted a 

 marker into the last carcass examined, crossed 

 to the other side of the line, and examined the 

 right front flippers as he returned to the 

 carcass with which he began. Examination of 

 about 100 seals in 10 minutes was followed by 

 a wait of 15 minutes, after which the worker 

 repeated the procedure, beginning with the last 

 carcass he had marked. During the 15-minute 

 interval, the tag- recovery man examined loose 

 flippers at the carcass dumping site or assisted 

 the tooth collector. 



Bull counts .-- The number of harem bulls 

 (adult males holding females) counted on the 

 Pribilof Islands has decreased eachyear since 



1961 (fig. 7). The number of harem bulls de- 

 pends on the numerical strength of two other 

 herd elements- -idle or reserve bulls (males 

 age 7 and older without females) and producing 

 females. Decreases in the number of harem 

 bulls, however, are believed to be the result 

 of the reduction in the number of producing 

 females. 



The number of idle bulls counted on land has 

 also been decreasing, following a sharp rise 

 from 1952 to 1960 (fig, 7), The decline in idle 

 bulls has been caused by extensive killing of 

 recent year classes through longer seasons 

 and increases in the maximum size of seals 

 taken. 



The counts of bulls in 1965 are given by 

 island and by rookery in appendix table 10, 

 and all counts of bulls since 1911 are presented 

 in appendix table 11. 



Females 



The maximum sustained yield of sealskins 

 should occur when the number of breeding 

 females is at some level below its natural 

 peak. For this reason, large numbers of fe- 

 males were purposely killed on the Pribilof 

 Islands from 1956 through 1963 to reduce the 

 population from the peak reached by about 

 1940 to a lower and more productive level. 

 Additional females were taken in 1964 and 



Figure 5. — Biological assistant taking tooth samples, byproducts plant, St. Paul 

 Island, 1965 (photo by Harry W. May). 



