Geographic range.—Central and western Pacific from the Hawaiian Islands south to Australia, probably also in the Indian Ocean. In Micronesia: Mariana Islands—Medinilla; Marshall Islands—Jaluit?
Characters.—Adult: A large, white sea bird, with brown wings and tail; face dark blue; bill horn-colored with base orange-yellow in males and pink or light red in females; feet olive in males and lead gray in females.
Immature: Resembles adult, but head, wings, tail, chin and throat dark brown; some white mottling may be present on back and rump; bill dark; feet lead colored.
Nesting.—Yamashina (1932a:407) reports the taking of 12 eggs on February 19, 1931, at Medinilla Island in the Marianas.
Remarks.—No specimen has been examined by me from the area reported upon. Little is known regarding the distribution of the Masked Booby in Micronesia. It is found on the island groups which surround Micronesia and future field observations probably will add to our knowledge of its occurrence in this area. It is known to be resident only in the northern Marianas.
Sula sula rubripes Gould
Red-footed Booby
Sula rubripes Gould, Syn. Birds Australia, pt. 4, 1838, app., p. 7. (Type locality, New South Wales = Raine Island.)
Pelecanus piscator Kittlitz, Obser. Zool., in Lutké, Voy. "Le Séniavine," 3, 1836, pp. 296, 299 (Lougounor = Lukunor); idem, Denkw. Reise russ. Amer. Micron. und Kamchat., 1, 1858, p. 351 (Lugunor).
Dysporus piscator Hartlaub, Proc. Zool. Soc. London, 1867 (1868), p. 831 (Pelew); Hartlaub and Finsch, Proc. Zool. Soc. London, 1868, pp. 9, 118 (Pelews); idem, Proc. Zool. Soc. London, 1872, p. 90 (Pelew); Finsch, Journ. Mus. Godeffroy, 8, 1875, pp. 6, 47 (Palau).