94 THE FUR SEALS OF THE PRIBILOF ISLANDS. 



sealers, but by the ludiaiis of the Northwest coast, whose catch consists maiuly of 

 females aud yearlings, and we get a further idea from the comi^arative scarcity of 

 3-year-old cows on the rookeries,' 



Not only are the females heavily handicapped by the weight of their unborn 

 oftspriug, but during three months of the year they are compelled, in order to 

 withstand the drain of the nursing young, to frequently go to sea in search of food, 

 while at that very time the great majority of males is on laud, or in the immediate 

 vicinity of the islands, safe frouj natural enemies. 



If the death rate among females was not so high as to have kept the breeding- 

 portion of the herd practically at a standstill year after year, the effects of pelagic 

 sealing would not have made themselves visible on the rookeries so rapidly as they 

 did. Evidence of the large number of deaths among females also ai)pears in the 

 comparatively small area of the rookeries as figured in Elliott's lirst report, when they 

 were nearly or quite at their' highest level. The bachelor seals seem to have increased 

 enormously prior to the occupation of the islands by the United States, but there does 

 not appear to have been any corresponding increase among the females, great though 

 their numbers actually were, and the breeding grounds form but a small part of the 

 entire area occupied by seals. The female i)ortion of the herd, the very one on which 

 depends not only the increase but the prescr\atiou of the seal race, always has been 

 and always will be the most susceptible to attack, and it is snuill wonder that its 

 ranks have been decimated by pelagic sealing. 



That the death rate is high is certain ; that it is variable is equally sure, for 

 climatic conditions, with their bearing on the all important question of food supply, 

 vary from year to year. No man can safely assert that because seals are abundant 

 one season they will be equally numerous the next; and for this reason, if for no other, 

 it would be dangerous to permit the killing of seals at sea even in limited numbei's; 

 while another point to be borne in mind is that while the numbers of the seals have 

 been greatly lessened, nothing has occurred to lessen the number of their enemies or 

 to change whatever natural causes may be injurious to them. 



If little can be said about the causes of mortality among seals, less can be said 

 regarding the comi)laints to which they may be subject, although, from the prompt 

 manner in which the weak or ailing are weeded out by natural (;auses, disease seems 

 to be more rare than it [)robably is iu reality. Cases of some complaint ai)i)areutly 

 related to mange are not infrequent, the hair being worn down short, the rough and 

 thickened epidermis showing through the hair.^ The examination of specimens of 

 the skin dried and preserved in alcohol failed to throw any light on the exact nature 

 of the disease, which, from the worn condition of the adjacent fur, seems to produce 

 intense itching. The trouble is usually on some part of the back, but one female was 

 seen on which the head was aflected. It is said that this complaint is of more frecjuent 

 occurrence now than formerly, but this may be simply because the seals are more 

 closely observed than they were. 



' These 3-year-old seals may be distinguished by their rather small size and their gray mustaches ; 

 they were particularly looked for in 1X97 in order that their abundance or scarcity iiiij;Lt form tlie 

 basis for some estimate as to tiie losses among seals up to 3 years, but it can simply be said tlia,< f lie 

 3-year-old cows form but a small part of the breeding herd, the majority being I years old and over. 



^ Seals suffering from this trouble were taken by the pelagic sealers olf the coast of Japan aud 

 gave rise to the rumor that seals branded on the Pribilofs had been cai)tured in Japanese waters. 



