1891.] BIRDS OF THE PHCENIX ISLANDS. 2!)1 



numbers. They were built of small dead twigs of the plants of the 

 island, placed a foot or so above the ground on the spreading 

 branches of the Sida and on the beaten-down tussocks of grass. The 

 nests were placed as near together as supports could be found, and 

 there were well-defined limits to the colonies, although the bushes 

 beyond these limits appeared to be just as well suited for the 

 purpose as those within. 



Each nest was occupied by a bird. As one approached some of 

 these took flight and joined the wheeling crowd overhead, but the 

 rest remained sitting and allowed themselves to be touched with the 

 nnizzle of my gun, only chattering their bills by way of remonstrance. 

 Both males and females were to be seen engaged in the duties of 

 incubation. 



The following table gives the points of difference which I noted 

 between tlie sexes : — 



Males. Females. 



Scarlet throat-pouch present. No throat-pouch. 



Long nape- and baek-phinies. No long nape-plumes. 



Bill -varies in colour from black to Bill varies iu colour from piuk to 



greyi. grey. 



Feet and skin round the eye black. Feet and skin round the eye red. 



Wing-coverts black. Wing-coverts pale brown. 



Breast and belly dark except for a Breast and fore part of belly white ; 



white streak on each side of the nape-band white to tawny. 



latter. No pale nape-band. 



A few of the birds had the white or pale tawny heads of the 

 immature plumage. They were in the proportion of about 1 to 100 

 of those in ordinary plumage. I saw none of these on the nests. 



The throat-pouch of the male is a most striking object. When 

 fully distended it reaches forward as far as the end of the bill and 

 downwards so as to completely hide the breast — a great smooth 

 semitransparent balloon of the most briUiant scarlet, which contrasts 

 finely with the dark metallic tints of the plumage. If any of the 

 birds in a group had their pouches distended, there were generally 

 several in this condition, as though they were vieing with one another 

 in the exhibition of their attractions. From several parts of the 

 group came a low vibrating note, a combination of a whistle 

 and a purr accompanied by the sound of the chattering of their bills. 

 While uttering this note the bird leans back on the nest, with the 

 head thrown right back, the pouch fully extended, and the wings 

 half spread and shaken with a quivering movement. The female 

 birds meanwhile were either wheeling overhead or sitting on the edge 

 of the nest near their admirers. 



The pouch is not rapidly filled or emptied. When a bird with a 

 half-distended pouch takes flight, the latter is carried from side to 

 side with the movement through the air, gradually diminishing in 

 size. In the undistended state the bare wrinkled skin is completely 



^ When the bills are grey, the colour is due to the rough surface and appears 

 to be a sign of age. 



