66 HAWAIIAN BIRDS. ' 



Description.— Adult male. Head and neck gamboge-yellow; back, edges 

 of secondaries of remiges, and rectrices olive-green, bri^ter on rump 

 and upper tail-coverts ; wing-coverts, remiges and rectriceg blackish brown, 

 Under parts olive-grey washed with olive-green, espepially on the sides 

 and flanks; belly greyish white; under tail-coverts, grey washed with 

 green; bill white with faint bluish tinge; legs flesh color. Length about 

 6.30 inches. 



Adult female. Above olive-green, brighter on head and rump; feathers 

 of back with dark olive centers. Beneath- smoky grey, passing into white 

 on abdomen ; sides and flanks olive-green. 



Juvenile plumage. Above dark olive-green; beneath a lighter shade of 

 same, washed with yellow on throat; lower breast and belly sulphur- 

 yellow. 



Psittirostra olivacea Rothschild. Oahu Ou. 



At one time, no doubt, the ou was as common upon the island 

 of Oahu as it now is on most of the other islands. In 1893 Mr. 

 Perkins saw a pair there, and Mr. Bryan informs us (Key of the 

 Birds of the Hawaiian Group, p. 54) that he saw an individual 

 in Moanalua valley as late as October, 1899. A few pairs may 

 still linger here and there. Still the bird is to be looked upon as 

 practically extinct on Oahu. 



The cause of the extinction of the ou upon Oahu seems to be 

 very obscure. The fruit of the ieie vine is the particular food of 

 the bird, and there are considerable tracts of timber on the moun- 

 tains of the island where this vine still abounds. So, too, there 

 are sections where the guava and the mamaki are still plentiful, 

 and the ou is very fond of their fruit and berries. There appar- 

 ently being no scarcity of food and- shelter, why should the ou 

 have disappeared from Oahu, and yet persist upon other islands 

 where the timbered areas are even more restricted ? 



The Oahu bjrd appears not to differ in any important partic- 

 ular from psittafea, and perhaps, as suggested by Mr. Rothschild, 

 is to be distinguished sub-specifically rather than specifically. The 

 chief differences, as indicated by Mr. Rothschild, are the buffy 

 whitish breast, abdomen and under tail-coverts of adult males of 

 olivacea, the breast being washed with olive and the sides olive- 

 green as contrasted with the olive-green under parts of adult 

 psittacea, the whitish being restricted to the middle of the lower 



