EXPEDITION TO LAYSAN ISLAND IN 1911. 



23 



west shore of the lagoon, in the tall grass, where a few nests containing 

 eggs and young birds were found. 



A pair made a nest not far from our sleeping quarters. The birds 

 seemed not to mind our presence, working away at the nest when we 

 were within 2 feet of it. After it was completed, the female bird died 

 while laying an egg. We saved the skin of the bird, also the egg, 

 which was removed intact. In a few days the male bird returned 

 with a new mate, and, much to our surprise, the birds took down the 

 nest, building a new one a few feet away. 



It seems strange that this bird should not be more common, as it 

 was formerly reported to be most abundant of the land birds. Pre- 

 sumably the poachers caught the miller bird, but we have no proof 

 of it, as no skins or other parts were found. Its numbers are kept in 

 check by the finches — at least we saw the latter eating the eggs of this 

 species. Undoubtedly, however, this has been their practice for 

 many years, and, unless the finches are more abundant than formerly, 

 it ought not to make any appreciable difference in the numbers of the 



miller bird. 



ISLAND BIRD CENSUS. 



An estimate of the number of each species of bird found on the 

 island was made. The method of estimating the number in the 

 several rookeries was as follows : After carefully measuring a rookery, 

 a square yard was selected that seemed to contain a fair average of 

 nests. Counting two birds to a nest we determined the number in a 

 rookery. In some cases this method could not be used, as some 

 species do not assemble in large numbers but nest in small colonies 

 among the other species. The map (p. 14) accompanying this report 

 is not a criterion as to the number of birds in the various rookeries, 

 but simply shows the location and approximately the area covered 

 by the species indicated thereon. To avoid confusion I have indi- 

 cated thereon only the birds that have sharply defined rookeries, 

 the others being more or less united. 



The following table shows at a glance the estimated numbers of 

 most of the island birds: 



Sterna fuliginosa 333, 900 



Sterna lunata 50, 000 



Anous stolidus 5, 500 



Micro nous hawaiiensis 3, 000 



Gygis alba Icittlitzi 75 



Diomedea immutabilis 180, 000 



Diomedea nigripes 85, 000 



Puffinus cuneatus 100, 000 



Puffimis nativitatis 75, 000 



JEstrelata hypoleuca 160, 000 



Bulweria bulweri 1,000 



Oceanodroma tristrami 3 



Pha'ethon rubricaudusZ 300 



Sulacyanops 65 



Sula piscator 125 



Fregata aquila 12, 500 



Anas laysanensis 6 



Porzanula palmeri 2, 000 



Numenms tahitiensis 250 



Charadrius dominicus fulvus ... 2, 000 



Arenaria inter pres 2, 500 



Himatione fraithii .- . . . 300 



Telespiza cantans 2, 700 



1, 016, 224 



