84 REPORT OF BRITISH COMMISSIONERS. 



intricate and ingenious series of calculations partly on this supposition,* 

 but there is now a very general consensus of opinion among those who 

 have studied this question on the Pribyloff Islands to the eftect that 

 tlie females are covered at or shortly after the expiry of the second 

 year from the time of their birth, and bear young in the third year from 

 that time or early in the fourth year of their age. The same ojiinion 

 was found to be held u])on the Commander Islands, and there is every 

 reason to believe that it is essentially correct. 



280. Both males and femalesleave the iskmds at the close of the season 

 in which they are born as "grey i)ups," the sexes being undistiuguish- 

 able to all outward apjiearance. In the following season they are 

 classed as yearlings, and it is probable that a large proportion of these 

 either do not land upon the islands at all or stay only for a short time 

 on shore. Such of the yearlings as are found upon the islands, however, 

 botli males and fenmles, consort with the holluschickie or bachelors. 



287. It appears, further, to be certain that the males arrive at virility 

 in their fourth year, and between this time and that in which they attain 

 their foil strength and size and are able to maintain their places on the 

 breeding rookery, when six or seven years old, they are often spoken of 

 as " half-bulls " or "reserves." They actually serve in the latter capacity, 

 and cover many of the females which escape the attentions of the older 

 males upon the rookery grounds, and in such cases the act of coition is 

 usually accomplished at sea. 



288. While the j^oints just referred to maybe supposed to have been 

 ascertained with moderate certainty, nothing is certainly known as to 

 the maximum ages attained by seals of the two sexes respectively, and 

 very little as to the total number of young which a female may bear 

 during the continuance of her fertility, or the number of years during 

 which the male retains his virility. Elliott conjectures that the females 

 may live to an age of 18 or 20 years. Bryant gives his reasons for sup- 

 posing that 12 years is about the average attained by the males.t 

 Veniaminov thought that the females in their prime bring forth every 

 year, and as they grow older, every second year. He states that, accord- 

 ing to ])ersons familiar with them, each female may in^oduce in the course 

 of her life ten or fifteen young or even more. J He admits, however, 

 that this is very uncertain, and the whole subject is, in fact, beset with 

 almost insuperable difficulties. All that is certain is that both males 

 and fenudes continue to perform their functions as breeders for a con- 

 siderable number of years. 



289. From what has been said as to the number of years required by 

 the respective sexes to reach maturity, it follows that any great loss 

 of young in the year of their birth can only begin to make itself appar- 

 ent on the rookeries, in the case of females, after the lapse of three 

 years, and in the case of males after five or six years. Thus in the 

 event of the killing of all or nearly all the young males of a certain 

 age, in any one year or series of years, a void of smaller or larger 

 dimensions is created in the supply of full-grown males for the rookery 

 grounds, which can only be partially bridged by the continuance on 

 the rookeries of the older and enfeebled males, which have j^assed their 

 natural term of retirement. If such killing is maintained from year to 

 year, the deterioration in the supply of virile males for the requirements 

 of the females, though slow and spread over several or many years, 

 must be continuous. Moreover, the lowering of the standard weight 



* Quoted by Elliott in United States Census Report, p. 141 et seq. 



t " Monogriipli of North American Pinnipeds," ]). 407. 



t Quoted iby Elliott in United States Census itcjjort, p. 141. 



