the season by another bull. As a rule, the mid-July bull is succeeded 
by a younger male which impregnates late-arriving young females. The ratio, 
(total number of pups born) / (total number of harems counted in mid-July) 
is called the “average harem" in records of the fur-seal industry (e.g., 
U. S. Bureau of Fisheries 1947, p. 74). The size of the average harem is 
discussed in appendix C. 
aos b u 

Figure 5. Idle bulls. Idle bulls along the landward 
edge of Gorbatch rookery at the height of the breeding season, 
15 July 1944. Among the idle bulls are a few bachelors 3 or 4 
years old. Idle bulls also cruise in the water along the sea- 
ward edge of the rookery searching for an opportunity to invade 
the breeding area, and several are visible on the rocks at the 
water's edge. The branded bull (right foreground) was presumably 
marked in the 1927-29 series and is 18 to 21 years old (VBS 1706). 
Bachelors 
Male seals after their first year and before age 7 are called 
bachelors (figures 1, 3, and 7)... They gather in large groups to sleep and 
play on hauling grounds near the breeding areas. Little is known of their 
coming and going during the summer, except that they appear on land in 
order of decreasing age, the 2-year-olds and yearlings arriving last. 
Ser 
