
Figure 6. A young harem bull. A tagged 7-~year-old 
bull holding a small harem at the edge of Tolstoi rookery. 
Note the metal tag at the base of his right front flipper. 
Few males hold harems before the age of 10 or 12, at which 
time they become large enough to force their way on to the 
breeding grounds (KWK 48 28). 
The objective of the sealers is to kill males 41 to 45 inches 
in length. From 1913 to 1918 age-length standards were established 
for male seals ages 1 to 6 by means of measurements taken by G. Dallas 
Hanna from known-age seals branded as pups in 1912 (U. S. Bureau of 
Fisheries, 1918, p. 96. See appendix D). The length of every male seal 
killed in the commercial harvest since 1918 is on record. The records 
include more than 1,500,000 seals, by day and place of kill, and have 
proved useful in the present study as indexes of the relative abundance 
of bachelors from one year to the next. 
Recent studies of the size-to-age relation in seals reveal that 
the age~length standards established before 1918 are no longer a true 
indication of age. For example, males measuring 41 to 45 inches in length 
have been considered 3-year-olds. Age studies between 1949 and 1952, based 
ante 
