FUR SEALS AND OTHER UFE, PRIBILOF ISLANDS, I914. 35 



between the numbers for 1910 and 1912, we may assume that the average harem does 

 the same. This gives 34.5 as the estimated average harem on Kitovi in 191 1, and 

 multiplying this by 1,369, the total number of harems, gives 47,230 as the estimated 

 total of pups. Assuming that this is two-thirds of the actual number gives 70,845, 

 total pups in 191 1, the best result that can be obtained with the data available. 



Considering now the other method, we find that a very reasonable argument may 

 be advanced that, since the herd was in a declining condition, the number of pups born 

 in 191 1 would not be smaller than the number born in 1912. The treaty abolishing 

 pelagic sealing went into effect December 15, 191 1. Therefore pelagic sealing was going 

 on in 191 1 only slightly less than in 1910. There is little doubt that from 10,000 to 

 15,000 cows were lost to the herd in 191 1 through this means. Since we know that in 

 spite of this drain the cows of 191 1 produced 81,984 pups in 191 2, it is reasonable to 

 suppose that the cows of 1910, having been subjected with the whole herd to one season 

 less of pelagic sealing, would produce at least as many pups as those of 191 1. From 

 this reasoning, therefore, the assumed births in 191 1 might be stated in round num- 

 bers as 82,000. It is evident, however, that pelagic sealing created many abnormal 

 conditions in the herd, and in view of the pup count of 191 4 showing practically no 

 increase over that of 1913, as well as various figures obtained by the Japanese on Robben 

 Island, it is unsafe to assume fixed rates of annual increase or decrease. There are too 

 many factors involved to make it possible to say with certainty that such an estimate 

 is a conservative one. 



Taking both estimates into consideration, the one of 70,845 and the other of 82,000, 

 it may be concluded that the number born in 191 1 was between 70,000 and 80,000. For 

 our purposes, and keeping on the side of conservatism, 75,000 may be taken as a number 

 open to no serious objections. Taking off 50 per cent for first year's mortality and 15 

 per cent for the second year, leaves 31,875 2-year-olds in 1913, of which half, or 15,937, 

 were males. 



It is necessary next to deduct the number of 2-year-old males killed in 1913. The 

 only basis for determining this is the weight of the skins, and, although this is known to 

 be unreliable, it furnishes the best approximation of the truth that can be obtained. 

 The food killings in 191 3 were mostly intended to include only 3-year-olds, but a number 

 of skins weighing less than 5^ pounds were taken. For purposes of an estimate made 

 before a thorough study of the subject of weights and ages, it may be assumed that 

 skins weighing under 5K pounds were those of 2-year-olds. Of 2,399 seals killed in the 

 calendar year 1913 there are records of weights of the skins of 2,357, of which 515 were, 

 on this basis, 2-year-olds. Subtracting this from 15,937 leaves 15,422 as the estimated 

 number of 2-year-old males at the close of the year 1913. Although it is probably too 

 high, 10 per cent k«s may be assumed for the next year in order to keep the estimate 

 on the safe side. This gives us 13,880 as the number of 3-year-old males in 1914. This 

 is purely an estimate, but in the light of past experience in the killing of large quotas 

 it can not be regarded as excessive. Three-year-olds were seen in large numbers on all 

 the hauling grounds and in all the food drives. On August 8 1,572 bachelors were 

 driven from Reef hauling ground and 447 were killed. At least 41 1 of these, or 26 per 

 cent of those driven, on the basis of the weight of the skins, were 3-year-olds. This 

 result might be applied in various more or less unsatisfactory ways to estimate the 

 total number of 3-year-olds, but it is of value principally as proof that seals of this class 



