Chlidonias leucopterus (Temminck)
White-winged Black Tern
Sterna leucoptera Temminck, Man. d'Ornith., 1815, p. 483. (Type locality, Coasts of the Mediterranean.)
Hydrochelidon leucoptera Oustalet, Nouv. Arch. Mus. Hist. Nat. Paris, (3), 8, 1896, p. 57 (Guam); Hartert, Novit. Zool., 5, 1898, p. 67 (Guam); Seale, Occ. Papers Bernice P. Bishop Mus., 1, 1901, p. 20 (Guam); Safford, Osprey, 1902, p. 70 (Marianas); idem, The Plant World, 7, 1904, p. 268 (Guam); Hartert, Vögel pal. Fauna, 13-14, 1921, p. 1686 (Guam); Kuroda, in Momiyama, Birds Micronesia, 1922, p. 51 (Guam).
Chlidonias leucoptera Hand-list Japanese Birds, rev., 1932, p. 194 (Guam); Hand-list Japanese Birds, 3d ed., 1942, p. 217 (Guam); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 55 (Angaur).
Geographic range.—Breeds in central and southern Eurasia. Winters from Africa east to Australia. In Micronesia: Mariana Islands—Guam; Palau Islands—Angaur.
Measurements.—One adult male has the following measurements: wing, 211; tail, 72; exposed culmen, 27; tarsus, 20; one adult female: wing, 210; exposed culmen, 25.5. These specimens were taken at the Palau Islands.
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).