Birds of Celebes: Fregatidae. 



885 



a low bush; eggs 1—2, of a chalky whiteness: 63.5X43.2 mm (Islands of Torres 

 Straits, North b 9). Interesting accounts of the breeding of the large form F. aquila 

 will be found in Baird, Brewer and Ridgway (8). 

 Distribution. Indian and Pacific Oceans. The range has not yet been satisfactorily deter- 

 mined. — Coasts of Celebes (Ribbe &Kuhn, P. & F. Sarasin, ? Rosenberg (? 2). 



A series of six Frigate-birds were obtained by the Drs. Sarasin on the coast 

 of Celebes, and these, with another from the island collected by Ribbe and 

 Kiihn, are before us. The difficulty of determining them is very great. We 

 are only able to state that one specimen may be determined as F. minor, and 

 that the others may perhaps belong to a slightly larger race, though smaller 

 than specimens of F. aquila from the Bahama Islands. The Frigate-birds breed 

 in great colonies, and we incline to the opinion that we have to do with in- 

 dividuals from two different colonies, which vary racially, as do members from 

 different colonies of the Edible-nest Swifts, Collocaliae. At present two species 

 of Fregata are recognised — F. aquila and F. minor, and most authorities write 

 of them as if it were the easiest matter imaginable to distinguish them, though 

 others confess themselves greatly perplexed. Among the opinions expressed it 

 may be cited that Schlegel (1) distinguished F. minor by its smaller size and 

 white flanks; Oustalet (el) would distinguish F. minor not only by its smaller 

 size, but by its naked throat and more uniform plumage; Legge (3) like 

 Schlegel by its smaller size and, in the adult male, by the white patch on 

 the flanks; Salvador! (5) by the smaller size of F. minor, its white flanks and 

 by its glossy green (more or less bluish) back and scapulars — as against violet 

 in F. aquila; Sharpe (b 7), having questioned the validity of F. minor elsewhere 

 (h 5), was again inclined to separate it, after examples from Borneo, by reason 

 of the "red" colour of the bill (Legge says "grey", Gould "bluish horn") and 

 much shorter wings and toes; Ridgway (10) found the plumage of F. minor 

 "not very obviously different" from F. aquila, while large specimens of the former 

 had much longer wings than small specimens of the latter, but the bill (culmen) 

 of F. aquila was found to measure more than 4.15 in. (105 mm), that of F. minor 

 less than this. 



Three adult, or nearly adult, specimens from Celebes in the Sarasin Col- 

 lection and the Dresden Museum want the white patch on the flanks, and 

 should therefore be F. aquila; but their size is not large, their bills under 

 105 mm and the upper surface more or less glossed with green, for which 

 reasons they should be F. minor, but, besides the absence of the white side- 

 patches, their bills are larger than in the more typical specimen of that bird 

 before us. They seem to break through the supposed line of separation between 

 F. minor and aquila and make it probable that the maintenance of the two names 

 is misleading, and that there are not two species of Frigate-bird, but, as sug- 

 gested above, a number of ancient colonies, the inhabitants of which differ more 

 or less from one another in size and other characters. Want of material renders 

 it advisable for us, however, to leave matters as they are for the present. 



