Vol. II, Pt. I] GIFFORD— BIRDS OF THE GALAPAGOS ISLANDS 49 



No. 1913, female, Hood Island, September 28, 1905, is 

 evidently a young bird starting on its first prenuptial moult. 

 The primaries are old and worn, and some feathers much 

 bleached and worn remain among the lesser coverts. In addi- 

 tion to the dusky bill and feet, this bird has a sharp line of 

 demarcation between the black and the white on the upper 

 breast. 



No. 1909, male, Indefatigable Island, July 16, is in fresh 

 plumage. The distal primary in each wing, however, is not 

 full grown, but is pulpy at the base. The feet are dusky com- 

 pared with those of adults, and it is probable that the specimen 

 is a young bird going through either its first prenuptial or 

 first postnuptial moult. Again the line of demarcation of the 

 black and white on the breast is sharp, while in adults such is 

 not the rule. 



No. 1888, male, Abingdon Island, September 18, 1906, is 

 in about the same state as the specimen just discussed, or per- 

 haps a little younger. The line of demarcation on the upper 

 breast is sharp, and the naked parts are dusky. It is difficult 

 to say whether this bird is completing its first prenuptial or its 

 first postnuptial moult. 



The following notes are on obvious adults : Five speci- 

 mens taken on Hood Island and Gardner-near-Hood in latter 

 September, 1905, are all in moult, and have primaries in some 

 stage of growth. As the sexual organs of these birds showed 

 signs oj. activity, and as we obtained young on the first of the 

 following February, it seems as though the moult in progress 

 is the prenuptial, and that this species moults its flight-feathers 

 twice a year. 



Four specimens from Indefatigable Island, secured during 

 the second half of October, are moulting. One has worn pri- 

 maries, another has new full-grown primaries, while the re- 

 maining two have the distal primaries still pulpy basally. 

 Three November individuals, however, are in fresh plumage, 

 the primaries just having attained full growth. In two cases 

 traces of a sheath are discernible at the base of the distal 

 primary. 



The next specimen in order of capture is a male taken on 

 James Island on December 26. Except for somewhat worn 

 primaries, this bird is in fairly fresh plumage, and has a con- 

 August 8, 1913 



