122 BULLETIN OF THE BUREAU OP FISHERIES. 



colonies, usually on the cliffs and rocky ledges fronting the sea. Besides the breeding 

 birds, there are a larger number which nest on the Alaskan mainland or in other parts of 

 the far North and merely visit the Pribilofs on their journeys to and from their vsdnter 

 homes, which in some cases are as far distant as the Hawaiian Islands. A number of 

 species of Asiatic distribution occur on the island and a few of these breed. In the case of 

 a few species, the specimens taken on the Pribilof Islands constitute the only records for 

 North America. It will be seen, therefore, that apart from their purely economic status, 

 which is the subject of the present account, the birds of the Pribilof Islands are of unusual 

 interest. 



The species which are abundant and of economic importance to the human inhabit- 

 ants fall into six natural groups. Mentioned in the order of their importance these 

 groups are the murres, auklets, gulls, ducks and geese, shorebirds, and cormorants. Some 

 of these groups are important also as furnishing food for the valuable herds of blue foxes. 

 Their value in this regard is discussed in the account dealing with that animal. 



MURRES. 



With the exception of the least auklet, the murres, or arries as they are usually 

 called, probably outnumber any other birds on the islands. They include two species, 

 the Pallas Murre {Uria lomvia arra) and the California Murre {Uria troile calijornica) . 

 The first named is slightly larger than the other with the back glossy black, while the 

 California Murre is of shghter build with the back more plumbeous. Both species 

 breed on St. George, Walrus, and Otter Islands. The murres of St. Paul are mainly, if 

 not entirely, the Pallas Murre. The two species are of nearly equal abundance, and for 

 present purposes may be considered together. The size of the birds, nearly equal to 

 the mallard, the ease with which they can be captured, and especially the immense size 

 of the nesting colonies, combine to make them an important economic feature. Many 

 of the birds are shot, especially in the spring, and the eggs are an important article of 

 food. The single egg is very large for the size of the bird, being at least twice the bulk 

 of a hen's egg. Many are taken from the cliffs of the two main islands, but the main 

 source of supply is Walrus Island, about lo miles from St. Paul. Here the birds nest 

 to the number of many thousands. It is the custom for the natives to go to this island 

 about the middle of June, when the birds have fairly started nesting, and to gather all 

 eggs from a certain area. About a week later the place is revisited and the area lately 

 denuded will be found restocked with fresh eggs. The birds will lay again, even if the 

 second set is removed, and in some cases even a fourth egg may be deposited, but as 

 the breeding ground is seldom revisited more than once in a season, the taking of eggs 

 causes practically no diminution in the species, but merely retards the breeding of a 

 part of the birds a week or two. This is shown by the fact that in spite of the eggs 

 having been gathered in this way for many years, practically all the available space on 

 Walrus Island is still occupied by the breeding hordes, and the various colonies in other 

 parts of the Pribilofs show no appreciable loss. The birds are never killed on the rook- 

 eries during the breeding season. 



GULLS. 



The gulls of economic importance are the Glaucous-winged Gull (Larus glaucescens), 

 the Red-legged Kittiwake {Rissa brevirostris) , and the Pacific or Black-legged Kittiwake 

 {Rissa t. pollicaris). The two last named occupy certain areas on all the islands, usually 



