TWO FUR SEAL PROBLEMS AND THEIR SOLUTION 



499 



the herd: A full count of the pups born in 

 1912 Avas accomplished, totaling 81,984. A 

 count was made also in 1913, giving 92,269, 

 a gain of approximately twelve and a half 

 per cent. A third count was made in 1914, 

 but by new investigators, and a gain of only 

 one per cent was found. In 1915 the count 

 was in charge of one of the government 

 agents Avho found a total of 103,527. Fortu- 

 nately the same agents had charge of the 

 count for 1916, finding a total of 116,977, a 

 gain of approximately thirteen per cent. We 

 thus have two sets of counts each with the 

 personal equation unchanged, and they give 

 respectively twelve and a half and thirteen 

 per cent for the annual gain in the herd. 

 These may be taken as fixing with reason- 

 able exactness the rate of growth at about 

 thirteen per cent. 



Although the settlement of this point must 

 await the ultimate age determination to be 

 useful finally in fixing the number of three- 

 year-old animals, male and female, it has 

 yielded immediately useful information. To 

 count the pups each season as the herd grows 

 is physically impossible, and some form of 

 estimate must be substituted to reach an 

 approximate determination of its condition 

 from year to year. It will be possible always 

 to make a close count of the breeding fami- 

 lies. From the five seasons in which the full 

 count of pups has been made, average harem 

 sizes for each individual rookery, for each 

 island separately, and for the herd as a 

 whole, are available which, when finally aver- 

 aged, can be applied to the count of harems 

 and defjended upon at any time to give a 

 close approximation of the size of the herd. 

 Second, as to the final age limit or life 

 span: In 1912 between five and six thousand 

 fur seal pups were branded on the crown of 

 the head with hot irons, giving a permanent 

 and readily recognizable identification mark. 

 It was expected that from the survivors of 

 this branding a certain number of animals 

 could be killed in 1913, and from very exact 

 animal and skin weights and measurements a 

 standard of the yearling seal obtained. A 

 further killing in 1914 would standardize 

 the two-year-old, in 1915 the three-year-old, 

 and in 1916 the four-year-old. Continued 

 observation of the remaining branded ani- 

 mals on the breeding grounds, season by sea- 

 son until their final disappearance, was then 



expected to fix within reasonable limits the 

 ultimate or average age. 



The standardization of the yearlings was 

 interfered with in 1913 by the fact that these 

 animals did not appear on the hauling 

 grounds in the breeding and killing season. 

 Incidentally this disproved the charge that 

 yearling seals had been killed, since, if they 

 do not come to the hauling grounds in the 

 killing season, they could not have been 

 killed as alleged. They did appear late in 

 the fall among the pups of the season, their 

 natural affinities. 



It is understood that enough of the 

 branded animals were killed in 1914 to fix 

 the standard of the two-year-olds. It may 

 be presumed that similar data were obtained 

 in 1915 and 1916 for the three and four- 

 year-olds. Whether the close and painstak- 

 ing observations necessary during the next 

 ten or twelve years to determine the final dis- 

 appearance of the branded animals will be 

 made remains to be seen. The shifting per- 

 sonnel of government agents, already fully 

 occupied with routine duties of administra- 

 tion, is not a hopeful source from which to 

 expect satisfactory results. If such observa- 

 tions are not available, the whole experiment 

 looking to a determination of the age limit 

 fails and Avill have to be begun over again. 



The need of reliable data regarding the 

 fur seal herd in these respects is one long 

 felt by those who at intervals have studied 

 briefly its problems. The Fur Seal Commis- 

 sion, of 1896-7 considered the matter of suf- 

 ficient importance to urge, as its one para- 

 mount recommendation, that a competent 

 naturalist be placed in charge of the herd 

 who should make its needs and problems his 

 life study. This recommendation was ig- 

 nored until 1909, when the fur seal service 

 Avas transferred to the Bureau of Fisheries. 

 The position of naturalist to the herd was 

 then created, but through the death, resigna- 

 tion, and serious illness respectively of the 

 first three appointees, the position, at the 

 close of the season of 1913, was still vacant 

 and systematic work yet to be begun. In 

 October of that year, the present Secretary 

 of Commerce abolished the position of natu- 

 ralist, on grounds of economy, leaving the 

 herd again to its own devices, except for such 

 desultory attention as the government agents 

 may be able to give it. 



