THE BERING SEA CONTROVERSY. 6 59 



189G and 1897, and the same diminution to one third or one fifth of the 

 former product may he assumed when we include also the results of the 

 hunting- at sea. 



This proposition needs little comment. It is a simple deduction 

 from the conditions of the preceding paragraph. The minimum 

 estimate of former conditions is the lowest possible figure that could 

 be in any way defended. The larger figure is apparently more nearly 

 correct. The quota of 1898, of which we now have the record also, 

 was about 18,000. It is not so stated in this paragraph, but the 

 inference is inevitable that what is thus given as the decline of the 

 '* yield of the hauling grounds " is equally the decline of the breed- 

 ing herd. A breeding herd which yielded without difficulty annu- 

 ally 100,000 killable animals (superfluous males of three years of 

 age) must be reduced to something like one fifth its former size when 

 it is able only with extreme difficulty to yield a quota of 20,000 such 

 animals. 



4. The death rate among young fur seals, especially among the pups, is 

 very great. While the loss amoug the pups prior to their departure from 

 the islands has heen found in the past two years to approach twenty per 

 cent of the whole mrmber born, and though the rate of subsequent mor- 

 tality is unknown, we may gather from the number which return each 

 year that from one half to two thirds have perished before the age of three 

 years — that is to say, the killable age for the males and the breeding age 

 for the females. 



The maximum and minimum figures here represent a division 

 of opinion. The larger figure of two thirds would even seem to be 

 a conservative estimate. The birth rate of 1897, as we know from 

 close estimate, was approximately 130,000; it must have been greater 

 in 1894, approaching 200,000. From this larger birth rate only 

 about 20,000 males survived (the quota of 1897). There was doubt- 

 less a like number of females, the sexes being equal at birth and 

 subject to like causes of natural loss. This gives a total of 40,000 

 in all, out of a birth rate of 200,000, which survived to the age of 

 three years. This is one fifth, and it is evident that the mortality 

 exceeds rather than falls below the maximum of two thirds. 



5. The chief natural causes of death among pups, so far as known at 

 present, are as follows, the importance of each being variable and more or 

 less uncertain : 



a. Ravages of the parasitic worm Uncinaria 1 ; most destructive on sandy 

 breeding areas and during the period from July 15th to August 20th. 



b. Trampling by fighting bulls or by moving bulls and cows, a source 

 of loss greatest among young pups. 



c. Starvation of pups strayed or separated from their mothers when 

 very young, or whose mothers have died from natural causes. 



d. Ravages of the great killer (Orca), known to be fatal to many of the 

 young, and perhaps also to older seals. 



