FUR-SEAL FISHERIES OF ALASKA, 1909. 31 
is to decide how many of these bachelors under normal conditions 
might be expected to mature as bulls. 
A table constructed on this basis follows : 
Increment of Bulls from Breeding Reservations. 
Age. 
1904. 
1905. 
1906. 
1907. 
1908. 
1909. 
3-year-olds 
1,000 
1,000 
900 
1,000 
900 
1,000 
900 
1,000 
900 
1,000 
900 
4-year-olds 
5-year-olds 
810 
810 
810 
810 
6-year-olds 
729 
729 
729 
7-year-olds 
647 
647 
Adult, bulls . 
583 
From this table we can see that, theoretically, we should have in 
1909, from the reservations of 3-year-olds made in 1904 and 1905, an 
increment of 583 adult, or 8-year-old bulls, and 647 7-year-olds, or 
quitters. This does not mean, of course, that the number of bulls 
present in 1908 would be increased by the number of new bulls noted 
above. A number of the 1908 bulls would have died by the following 
year. It means that this number of young bulls would be available 
to offset the mortality among adult bulls occurring during the interval 
between the seasons of 1908 and 1909. Any increase in bulls noted 
in the latter year would represent the excess of incoming young bulls 
over the loss by death of old bulls. 
It will now be interesting to note to what degree this theoretical 
computation agrees with the facts as demonstrated by the actual 
counts made during the last season. The table shows that 583 new 
full-grown bulls should be present in 1909. The count of harems 
made in 1909 shows that the number of harems in 1908 has been 
maintained and that we have in 1909 an increase of 35 harems on the 
two islands, and of 48 full-grown adult bulls that were without 
cows, a net increase in adult bulls of 83, in addition to an increase of 
67 in the 7-year-old quitter class. 
This actual increase in the number of bulls shows that the theoret- 
ical computation is correct in so far as to indicate a comfortable 
increase in bulls in 1909. The number of these new bulls that did 
actually take station on the rookeries is undeterminable, and to that ex- 
tent we can not verify the table. We do know that a number of young 
bulls had harems in 1909 for the first time, and that these incoming 
young bulls were sufficient not only to fill the gaps created by the 
death of old bulls but to increase the actual number apparent on the 
rookeries by 83 harem masters and idle. When we consider further 
the increase of 67 quitters, or 7-year-olds, a total increase of 150 
breeding males, we may feel that we have received, in a modified 
degree at least, the benefit of the reservations which the theoretical 
computation indicates should have been felt. 
