Tachypetes aquilus Finsch, Ibis, 1880, p. 333 (Taluit); idem, Journ. f. Ornith., 1880, pp. 296, 310 (Ponapé, Kuschai); idem, Ibis, 1881, pp. 109, 115 (Kuschai, Ponapé); Schmeltz and Krause, Ethnogr. Abth. Mus. Godeffroy, 1881, pp. 299, 353 (Mortlock, Ruk).
Fregata aquila Salvadori, Ornith. Papuasia, 3, 1882, p. 403 (Carolines, Marshalls); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6, (1890-1891), p. 71 (Ruk, Luganor, Ponapé, Ualan, Marshalls); Ogilvie-Grant, Cat. Birds British Mus., 26, 1898, p. 443 (Carolines, Marshalls); Finsch, Deut. Ver. zum Schultze der Vogelwelt, 25, 1900, p. 452 (Ponapé, Kuschai, Marshalls); Seale, Occ. Papers Bernice P. Bishop Mus., 1, 1901, p. 24 (Guam); Safford, The Plant World, 7, 1904, p. 267 (Guam); Schnee, Zool. Jahrbücher, 20, 1904, p. 390 (Marschall Inseln); Safford, Contr. U. S. Nat. Herb., 9, 1905, p. 80 (Guam); Cox, Island of Guam, 1917, p. 22 (Guam).
Fregata aquila palmerstoni Kuroda, in Momiyama, Birds Micronesia, 1922, p. 35 (Carolines, Marshalls).
Fregata minor peninsulae Mathews, Syst. Avium Australasianarum, 1, 1927, p. 233 (Carolines, Marshalls); Peters, Check-list Birds World, 1, 1931, p. 96 (Carolines?, Marshalls?).
Fregata minor palmerstoni Hand-list Japanese Birds, rev., 1932, p. 186 (Yap, Faraulep, Truk, Lukunor, Ponapé, Kusaie, Namu, Likieb); Bryan, Guam Rec., vol. 13, no. 2, 1936, p. 15 (Guam); Yamashina, Tori, 10, 1940, p. 676 (Maug, Bikar).
Fregata minor minor Hand-list Japanese Birds, 3d ed., 1942, p. 207 (Maug, Yap, Faraulep, Truk, Lukunor, Ponapé, Kusaie, Namu, Bikar, Likieb).
Fregata minor Borror, Auk, 64, 1947, p. 416 (Agrihan).
Geographic range.—Eastern Indian Ocean to western Pacific Ocean. Limits of range not certainly known. In Micronesia: Mariana Islands—Agrigan, Maug, Saipan, Guam; Caroline Islands—Yap, Faraulep, Truk, Lukunor, Ponapé, Kusaie; Marshall Islands—Namu, Bikar, Likieb, Kwajalein, Bikini.
Characters.—Adult male: Large sea bird with deeply forked tail; blackish but wing-coverts paler; head and back glossy purple and blue; breast lighter than belly. Adult female: Resembles adult male, but head blacker; chin and throat grayer; breast more whitish. Immature: Resembles adult, but head and throat whitish washed with buff; breast dark brown; belly whitish.