104 THE FUR SEALS OF THE PRIBILOF ISLANDS. 



times, there being 1!) drives, iiicliidiiig- .'U liauling grounds. Ju 1S94 but 14 drives 

 were made from 15 hauling grounds and in 1895 12 drives from an equal number 

 of hauling grounds. The quota of 30,0()() taken in 1890 was therefore artected in a 

 measure by tlie nature of the killing of the seasons immediately preceding. The 

 quota of 1897 is more nearly normal, but with the years immediately preceding it 

 can not properly be compared. 



But if these matters have tended to confuse the data which might have led to a 

 definite measure of decline, they do not obscure the fact of decline. This is every- 

 where distinct and unmistakable. 



THE EVIDENCE OF DECLINE. 

 ABANDONED GROrNDS. 



To the eye of the observer [)erhaps the most striking proof of decline is in the 

 abandoned rookery spaces. On the rear and on either side of the present rookery 

 areas are great tracts of ground which were once occupied, but which are now grass- 

 grown. The evidence of former occupation is to be seen in the felt like matting of 

 hair over the surface, in the smooth condition of the stones, worn by the moving 

 animals, and especially in the peculiar vegetation covering the area. These abandoned 

 grounds are now covered with fine yellow grass, known as "se.al grass,'' which grows 

 here and nowhere else. 



GRASS-GROWN AREAS. 



On some of the rookeries this grass-grown area shows three distinct stages. 

 Close to the space at present occupied is a narrow belt of ground, which is still occasion- 

 ally waiulered over by the seals, and on which the grass is just beginning to spring up 

 in spots protected by stones. This area shades imperceptibly into the absolutely 

 bare region now regularly occupied. Behind this space lies an area of dark green 

 grass, covering ground not now entered by the seals. The luxuriant growth of this 

 grass is due to the fertilizing matter in the more recently abandoned grounds. 

 Beyond this there is an extensive area of thinner yellowish grass of the same general 

 character, its less vigorous growth probably connected with the impoverished condition 

 of the soil. 



THEIR EXTENT. 



On several of the rookeries these three areas are clearly defined, and on all of 

 them the yellow-grass area is very extensive. On the hauling ground of Lukauin 

 rookery measurements made during the season of 189(j show the area of dark grass to 

 be 1(J feet in width and the area of yellow grass 04 feet. The area on which the grass 

 is just starting is less definite, and can not be measured accurately. The outward 

 line of the yellow-grass region marks the extreme limit of ground at any time occupied 

 by the seals. The dark green area marks a stage of more recent abaiulonment. 



On certain hauling grounds the area of abandoned territory is anywhere from ten 

 to twenty times the area at present occupied. This, however, does not mean that 

 there has been a corresponding decrease in the bachelor herds. Observations show 

 that a small band of bachelors can in a few days denude a large grass-grown area if 

 they begin to wander and sleep upon it. Five or six times the present number of 

 bachelors would doubtless denude all tliese areas. 



