248 



SNODGRASS AND HELLER 



been at least six months old. They were fed by the adults with dis- 

 gorged flying fish (^Exoccetus volitans) and young specimens of Hetn- 

 iramphus. These immature birds appear to remain on the nest for a 

 long time, perhaps nearly a year, being fed by the parents ; and re- 

 ciprocate by incubating the eggs. The young when just hatched are 

 naked, but soon become covered with a white down. 



17. SULA NEBOUXI Milne-Edwards. 



Sula nebouxi Milne-Edwards, Ann. Soc. Nat. Zool., xiii, p. 37, pi. 14, 

 1882 (Chile). — RiDGVVAY, Proc. U. S. Nat. Mus., xix, p. 596, 1896 

 (Galapagos). — Rothschild and Hartert, Novit. Zool., vi,p. 596, 1899. 



Range. — P,^cific coast of tropical America and the Galapagos 

 Islands. 



This is the most common and most widely spread Sulaoi the archi- 

 pelago. We observed it about all of the islands except Culpepper, 

 although at Wenman it is rare. Its breeding habits are different from 

 those of both S. variegata and S. piscatrix websteri in that it invari- 

 ably nests on cliffs. During the winter the cliffs about Tagus Cove, 

 Albemarle, afford a roosting place for a large number of these birds, 

 who sit on the ledges in an almost upright position, seldom assuming 

 the squatting goose-like attitude of the other two species. They are 

 very quiet birds ; even when a large number are together on the face 

 of a cliff it is only occasionally that one is heard to make any sound. 

 Their notes and their voice are very similar to those of S. variegata^ 

 consisting of a harsh squawk and a whistling sound. They are expert 

 divers and often drop almost vertically head downward from great 

 heights into the water in order to capture a passing fish. Under the 

 water they turn and soon come to the svirface. The Harris expedition 

 reports this species as breeding on Hood and Gardner (near Charles) 

 Islands during the latter part of October and on Abingdon Island in 

 August. We found it nesting on Albemarle and Narboro in March 

 and on Hood in May. 



MEASUREMENTS OF ADULT SPECIMENS OF Sultt tieboUXt. 



