Acrocephalus luscinia Hartert, Novit. Zool., 5, 1898, p. 57 (Guam, Saipan); Seale, Occ. Papers Bernice P. Bishop Mus., 1, 1901, p. 53 (Guam, Saipan); Matschie, Journ. f. Ornith., 1901, pp. 112, 113 (Guam, Saipan); Safford, Osprey, 1902, p. 69 (Guam); Dubois, Syn. Avium, 1, 1902, p. 369 (Marianne); Safford, Amer. Anthro., 4, 1902, p. 711 (Guam); idem, The Plant World, 7, 1904, p. 264 (Guam); idem, Contr. U. S. Nat. Herb., 9, 1905, pp. 30, 79 (Guam); Reichenow, Die Vögel, 2, 1914, p. 545 (Marianen); Cox, Island of Guam, 1917, p. 21 (Guam); Kuroda, in Momiyama, Birds Micronesia, 1922, p. 67 (Guam, Saipan); Bryan, Guam Rec., vol. 13, no. 2, 1936, p. 25 (Guam); Thompson, Guam and its people, 1942, p. 23 (Guam); Strophlet, Auk, 1946, p. 539 (Guam).
Conopoderas luscinia Mathews, Syst. Avium Australasianarum, 2, 1930, p. 594 (Marianas); Hand-list Japanese Birds, rev., 1932, p. 177 (Marianas).
Conopoderas luscinia hivae Yamashina, Bull. Biogeogr. Soc. Japan, 12, 1942, p. 81 (Type locality, Saipan); Hand-list Japanese Birds, 3d ed., 1942, p. 196 (Almagan, Saipan).
Conopoderas luscinia luscinia Hand-list Japanese Birds, 3d ed., 1942, p. 197 (Guam).
Acrocephalus luscinia luscinia Mayr (part), Birds Southwest Pacific, 1945, p. 294 (Guam, Saipan, Almagan); Stott, Auk, 1947, p. 526 (Saipan); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 67 (Guam).
Geographic range.—Micronesia: Mariana Islands—Guam, Saipan, Almagan.
Character.—Adult: A rather large warbler with long, curved bill; upper parts near "Saccardo olive"; feathers of head grayer because of darker shafts; rump paler and browner; lores dark; supraloral stripe light buffy-yellow; auriculars, cheeks, and sides of neck slightly darker; chin, throat, breast, and abdomen pale buffy-yellow; tibia darker and more olivaceous-brown; under tail-coverts pale yellow-buff; wing and tail feathers brown, edged with ochraceous; under wing grayish, inner edges lighter; axillaries pinkish-white; upper mandible dark horn colored; lower mandible lighter yellow; feet light gray; iris brown. Female resembles male but is slightly smaller.
Table 37. Measurements of Acrocephalus luscinia
Table 37. Measurements of Acrocephalus luscinia
| Subspecies | No. | Sex | Wing | Tail | Exposed culmen | Tarsus |
| A. l. luscinia | 11 | males | 84 | 83 | 36.0 | 30.5 |
| (81-86) | (80-86) | (35.5-39.0) | (30.0-31.0) | |||
1 | female | 78 | 73 | 37.0 | 28.5 | |
| A. l. syrinx | 31 | males | 78 | 71 | 26.5 | 26.5 |
| (76-80) | (68-75) | (25.0-27.0) | (25.0-29.0) | |||
12 | females | 75 | 68 | 25.5 | 26.0 | |
| (74-78) | (65-70) | (24.0-27.0) | (24.0-26.0) |