NUMBER OF MALES NEEDED. 53 



idle bulls, since all tlie cows are appropriated by the two or three lines of bulls 

 between the water and the clitt'. The small size of many harems is thus due to their 

 beinj? located in the inner portion of the rookery, where tlie bulls are unable to obtain 

 many cows, or where they obtain them by capture. Where the harems are small the 

 bulls appear to be less active and quarrelsome than where they are large, as if they 

 fnlly understood that it is less trouble to manage a small family than a large one. 

 This, however, maj" be a misinterj)retation of the facts in the case, for the smalluess 

 of the harem may have been due to the inability of the bull, on account of lack of 

 fighting qualities, to secure a large number of cows. 



If 35 cows is the minimum average for a harem, 50 or 60 would be what might be 

 called a good working proportion, and so long as the harems do not, on the average, 

 exceed this, there is no reason to suppose that the number of bulls is too small. The 

 small proportion of bulls actually necessary for the continuance of the fur-seal herd 

 is indicated by the conditions on Bering Island, where for many years every male 

 over a year old which could be secured has been promptly killed. Not only is there a 

 complete absence of idle bulls, but on the South rookery there are at most only 6 bulls 

 to 500 to 600 cows, the exact number of the latter being unknown. Notwithstanding 

 this small number of adult males, there is no evidence that, with the aid of the 

 younger males, it is not quite sufilicieut for breeding i)urposes, since there is no 

 apparent dearth of pups. 



This is not brought forward as an argument in favor of such close killing, which 

 under ordinary circumstances would be wholly unjustifiable, but to show how few 

 bulls are actually needed. The justification for this close killing is found in the 

 existence of pelagic sealing, which spares nothing, and renders it proper and desirable 

 to secure every available male seal on land, so as to leave as few as possible to be 

 killed at sea. The difiiiculty of so exterminating the males that the seal herd would 

 not recuperate if left to itself is well shown by the history of Kobben Island,' which 

 ever since 1854 has suffered from the most reckless slaughter, every effort having 

 been made time and again to secure every individual seal on the island. And yet, 

 again and again, after brief periods of rest, the seals have been found in greater or 

 less numbers, and even in 1896, after forty years of slaughter, there were about 1,000 

 seals of all kinds left, and it was possible to secure 260 skins. 



Robben Island is also a good illustration of what would happen were it possible 

 to put an end to pelagic sealing, for if seals continue to exist in any numbers when 

 their sole protection is preservation from being killed on land, it is easy to see how 

 they would increase if not taken at sea. 



The size of the harems and the number of surplus bulls is a safe guide to the 

 condition of the rookeries for breeding purposes, the increase or decrease of the total 

 number of seals being naturally quite another thing, although the two should be 

 carefully compared with one another. If the number of surplus bulls is large, and 

 the size of the harems small, either the rookeries are shrinking or the number of 

 bulls increasing, and immediate steps should be taken to ascertain which is the 

 case, in order to decide whether more seals inay be advantageously killed, or whether 

 there is an unsuspected number of deaths among the cows. The total disajipearance 

 of the idle, waiting, or reserve bulls, as they have been variously called, would be a 

 warning of the most emphatic nature to immediately lessen the number to be killed, 



' See Stejueger, The Russian Fur Seal Islands, pp. 54-58. 



