94 THE FUR SEALS OF THE PBIBILOF ISLANDS. 



sealers, but by the Indians of the Northwest coast, whose catch consists mainly of 

 females and yearlings, and we get a further idea from the comparative scarcity of 

 3-year-old cows on the rookeries.' 



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

 offspring, 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 o| food, 

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

 vicinity of the islands, safe from 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 staudstill 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 amoiig females also appears in the 

 comparatively small area of the rookeries as figured in Elliott's first 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 corresiJonding 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 portion of the herd, the very one on which 

 depends not only the increase but the preservation of the seal race, always has been 

 and always will be the most susceptible to attack, and it is small 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 numbers ; 

 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 complaints to which they may be subject, although, from the prompt 

 manner in which the weak or ailing are weeded out by natural causes, disease seems 

 to be more rare than it probably is in reality. Cases of some complaint apparently 

 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 affected. It is said that this complaint is of more frequent 

 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 1897 in order that their abundance or scarcity might form the 

 basis for some estimate as to the losses among seals up to 3 years, but it can simply be said that the 

 3-year-old cows form but a small part of the breeding herd, the majority being 4 years old and over. 



2 Seals suffering from this trouble wore taken by the pelagic sealers off the coast of Japan and 

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



