SEAL LIFE ON THE PRIBILOF ISLANDS. 31 



The thinning out of the breeding seals and the consequent recedence 

 of the breeding limits toward the beaches is followed by the encroach- 

 ment of grass upon the bare ground but recently occupied by seals. 

 Attention is called to a series of photographs taken annually which are 

 illustrative of this feature. 



It is impossible to Tepresent satisfactorily the decrease of the rook- 

 eries by photographs or charts. The former are limited in number and 

 have frequently to be taken from unfavorable points, while the reduction 

 of a great tract more or less occupied by seals to the limits of a small 

 photograph is often misleading except to those familiar with the ground. 

 The case of the charts is similar, the changes in extensive areas of 

 land not being impressive when indicated upon charts of small scale. 

 Special attention is called, however, to the large panoramas taken from 

 Stations 5, 17, and G, showing the large rookeries of Northeast Point, 

 Polavina, and Keef. In all of these very comprehensive views the 

 decrease in the number of seals and the withdrawal of the breeding 

 limits toward the sea front is apparent. 



ST. PAUL ISLAND. 



JSfortheast Point rooJcery. — The thin patches of seals upon each side of 

 Sea Lion Point are reduced in numbers and area. From station 6 to 

 the point two important breaks occur at points opposite the marshes. 

 From the point to Station 5 the rookery has visibly narrowed and the 

 seals have decreased in numbers. From Hutchinson Hill one of the 

 most imijortant changes of the year is visible. The photograph from 

 Station 5 shows the wide rookery ground to be narrower than ever 

 before. At only one point were young seals born as far back as the 

 base of the hill. At Station 4 the change is amply shown by the pho- 

 tograph, which, although taken eleven days later than in 1894, shows 

 no indication of seals spreading to their former limits. South.of Station 

 4 the seals for the first time failed to cover an important tract extend- 

 ing back in the direction of Hutchinson Hill. This is shown in the 

 photograph from Station 3. The animals usually somewhat massed at 

 this i^oint have found room upon the immediate beach slope. From 

 Station 3 to Station 1 the breeding seals are confined to the narrow 

 beach slope, very difficult of examination. Here the rookery is exceed- 

 ingly thin, which is indicated to a slight degree in rather unsatisfac- 

 tory photographs. The decrease in the number of seals at this great 

 rookery since 1894 is very marked. 



Polavina roolcery. — The main rookery, situated on a comparatively 

 level tract, is shrunken perha])s aO per cent in dimensions, and at no 

 point extends back to the limits of 1894. The small communities occu- 

 pying the ledges under the cliffs north of the point were much reduced 

 in numbers, and with the exception of a few stragglers did not overlap 

 on the plateau above. The photograph of the main rookery, taken at 

 short range, shows the breeding line to have receded toward the beach, 

 while the level ground at the left remained unoccupied. Another view 

 from Station 21, at still shorter range, shows a loss of seals from the 

 foreground and extreme background. 



At Little Polavina rookery the branches of the rookery extending 

 back on the plateau have been absorbed, while the remnant along the 

 cliff is thinned and lies in patches. Foggy weather prevented satis- 

 factory i)hotographic work. 



Lulan)ion rookery. — The breeding line here was drawn somewhat 

 lower than usual, and at no time during the season were the seals- 



