Geographic range.—Breeds in northern Siberia. Ranges east to Alaska and south to the Philippines and the China coast. In Micronesia: Mariana Islands—Agrihan.
Remarks.—The Herring Gull is ascribed to Micronesia on the basis of one bird obtained by Marche in January, 1889, at Agrihan in the northern Marianas and reported on by Oustalet (1896:56). The gull is considered a straggler to the northern Marianas from the northward. Stott (1947:525) observed a gull, which was thought to be this species or Larus ridibundus, at Lake Susupe, Saipan, in 1945.
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.