Specimens examined.—Total number, 6 (3 males, 3 females), as follows: Palau Islands, USNM—Angaur, 1 (Sept. 21); AMNH—exact locality not given, 5 (Oct. 13).
Remarks.—The White-winged Black Tern was first collected at Guam in October, 1887, by Marche and reported on by Oustalet (1896:57). It was later taken at the Palau Islands by Coultas in 1931, and by the NAMRU2 party at Angaur in 1945. The bird is seemingly an uncommon winter visitor to Micronesia.
At Angaur, the NAMRU2 party obtained one of four terns seen at a small fresh water lake. Coultas took five birds at the Palau Islands. He writes (field notes) that a flock of 14 of the terns appeared at the island following a heavy typhoon. All birds examined are in winter plumage (September and October).
Sterna hirundo longipennis Nordmann
Black-billed Common Tern
Sterna longipennis Nordmann, in Erman's Verz. Thier. Pflanz., 1835, p. 17. (Type locality, Mouth of the Kutchui River, Sea of Okhotsk.)
Sterna longipennis Hartlaub and Finsch, Proc. Zool. Soc. London, 1872, pp. 90, 112 (Pelew); Finsch, Journ. Mus. Godeffroy, 8, 1875, pp. 5, 41 (Palau); Salvadori, Ornith. Papuasia, 3, 1882, p. 440 (Pelew); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 74 (Pelew); Saunders, Cat. Birds British Mus., 25, 1896, p. 67 (Pelew); Takatsukasa and Kuroda, Tori, 1, 1915, p. 62 (Pelew); Kuroda, in Momiyama, Birds Micronesia, 1922, p. 21 (Pelew).
Sterna hirundo longipennis Hand-list Japanese Birds, rev., 1932, p. 195 (Palau); Hand-list Japanese Birds, 3d ed., 1942, p. 218, (Palau); Mayr, Birds Southwest Pacific, 1945, p. 25 (Palau).
Geographic range.—Breeds in northeastern Asia. Winters south to Melanesia. In Micronesia: Palau Islands—exact locality unknown.
Remarks.—Finsch (1875:41) states that Heinsohn and Kubary obtained specimens of this tern from the Palau Islands for the Godeffroy Museum. These are the only records for the occurrence of the Black-billed Common Tern in Micronesia.