416 



LETTERS OF NATURALISTS. 



PRESENT NUMBERS COMPARED WITH FORMER ABUNDANCE. 



The rookeries ou both St. Paul and St. Georjue Islands bear nnmis- 

 takable evidence of having" undergone great reduction in size during 

 the past few years. This evidence consists (1) in the universal testi- 

 mony of all who saw them at an earlier i>erio(l, and (li) in the presence 

 upon the back part of each rtK)kery of a well-marked strip or zone of 

 grass-covered land, varying from 100 to 500 feet in width, ou which the 

 stones and bowlders are flipper- worn and polished by the former move- 

 ments of the seals, and the grass is yelh* wish-green in color and of a 

 different genus {(rU/ccriaan<jnstat<i) from the rank, high grass usually 

 growing immediately behind it {Ulymus mollis). In many places the 

 ground between the tussocks and hummocks of grass is covered with a 

 thin layer of felting, coiuposed of the shed hairs of the seals matted 

 down and mixed with excrement, urine, and surface soil. The exact 

 year Avhen this yellow-grass zone was last occupied by seals is difl&cult 

 to ascertain, but the bulk of testimony points to 188G or 1887. The 

 aggregate size of the areas formerly occupied is at least foiu" times as 

 great as that of the present rookeries. 



CAUSES WHICH LED TO THE DEPLETION OF THE ROOKERIES. 



The seals which move northward along the coast of the northwestern 

 United States, British Columbia, and southeastern Alaska from Janu- 

 ary until late in June are chiefly pregnant females, and about 90 per 

 cent of the seals killed 'by pelagic sealers in the North Pacific are 

 females heavy Avith young. For obvious reasons many more seals are 

 wounded than killed outright, and many more that are killed sink 

 before they can be reached, and consequently are lost. As each of 

 these contains a young, it is evident that several are destroyed to every 

 one secured. 



For several years the pelagic sealers Avere content to pursue their 

 destructive work in the North Pacific, but of hite they have entered 

 Bering Sea, where they continue to capture seals in the Avater through- 

 out the entire summer. The females killed during this period are giv- 

 ing milk and are aAvay from the islands in search of food. Their young 

 starve to death on the rookeries. I saw vast luimbers of such dead 

 pups on the island of St. Paul last summer (1801), and the total num- 

 ber of their carcasses remaining on the Pribilof Islands at the end of 

 the season of 1891 has been estimated by the United States Treasury 

 agents at not less than 20,000. 



The number of sealskins actually secured and sold as a result of 

 pelagic sealing is shown in the following table: 



