Birds of Celebes: Fregatidae. 
885 
a low bush; eggs 1 — 2, of a chalky -wliiteness: 63.5X43.2 mm (Islands of Torres 
Straits, North b .9). Interesting accounts of the breeding of the large form jP. aquila 
will be found in Baird, Brewer and Eidgway (8). 
Distribution. Indian and Pacific Oceans. The range has not yet been satisfactorily deter- 
mined. — Coasts of Celebes (Eibbe&Kiihn, P. & P. Sarasin, ? Eosenberg I). 
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 Eibbe and 
Kuhn, 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 (e J) would distinguish F’. mmor 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; Salvadori (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 
(b5), 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 (culmeii) 
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. 
