Acrocophalus luscinia syrinx (Kittlitz)
Nightingale Reed-warbler
Sylvia syrinx Kittlitz, Mém. Acad. Imp. Sci. St. Petersbourg, 2, 1835, p. 6, pl. 8. (Type locality, Lugunor and Ulcei = Woleai.)
Sylvia syrinx Kittlitz (part), Obser. Zool., in Lutké, Voy. "Le Séniavine," 3, 1836, p. 297 (Lougounor); idem, Denkw. Reise russ. Amer. Micron. und Kamchat., 2, 1858, p. 92 (Ualan, Lugunor, Ulea).
Eparnetes Reichenbach, Syst. Avium, 1850, pl. 57 (no locality = Carolines); Bonaparte, Comptes Rendus Acad. Sci. Paris, 41, 1855, p. 1111 (Carolines).
Tatare syrinx Hartlaub, Archiv f. Naturgesch., 18, 1852, p. 131 (Ualan, Lugunor); Pucheran, Voy. Pôle Sud, 3, 1853, p. 92 (Hogoleu = Truk); Hartlaub, Journ. f. Ornith., 1854, pp. 164, 168 (Hogoleu); Gray, Cat. Birds Trop. Is. Pacific Ocean, 1859, p. 14 (Ualan); Sharpe, Cat. Birds British Mus., 7, 1883, p. 527 (Carolines); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 41 (Ruk, Ualan, Luganor, Uleei, Nukuor, Ponapé); Oustalet (part), Nouv. Arch. Mus. Hist. Nat. Paris, (3), 7, 1895, p. 210 (Ruk, Ponapi, Mortlock, Kusaie, Uleei, Nukuor).
Acrocephalus orientalis Pelzeln, Reise "Novara," Vögel, 1865, pp. 63, 162 (Puynipet, Lugunor, Ulcei).
Calamodyta syrinx Gray, Hand-list Birds, 1, 1869, p. 208 (Ualan); Giebel, Thes. Ornith., 1, 1872, p. 529 (Carolin.).
Calamoherpe syrinx Finsch, Journ. Mus. Godeffroy, 12, 1876, p. 17 (Ponapé, Lugunor, Ruck, Ualan, Uleei); idem, Proc. Zool. Soc. London, 1877 (1878), p. 778 (Ponapé); idem, Journ. f. Ornith, 1880, pp. 287, 297 (Ponapé, Ruck, Mortlocks, Kuschai); idem, Proc. Zool. Soc. London, 1880, p. 575 (Ruk, Ponapé); idem, Ibis, 1881, pp. 108, 112, 115, 247 (Kuschai, Ruck, Ponapé, Mortlocks); Schmeltz and Krause, Ethnogr. Abth. Mus. Godeffroy, 1881, pp. 298, 330, 353 (Ponapé, Mortlocks, Nukor, Ruk); Finsch, Ibis, 1883, p. 143 (Ruck); idem, Mitth. Ornith. Ver. Wien, 1884, p. 49 (Ponapé); idem, Sammlung wissensch. Vorträge, 14 ser., 1900, p. 659 (Carolinen).
Acrocephalus syrinx Seebohm, Cat. Birds British Mus., 5, 1881, p. 100 (Ponapé); Tristram, Ibis, 1883, p. 44 (Ponapé, Ruk, Mortlock, Lugunor, Uleei); idem, Cat. Birds, 1889, p. 152 (Ponape, Ruk); Nehrkorn, Kat. Eiers., 1899, p. 33 (Ponapé, Ruk); Hartert (part), Novit. Zool., 5, 1898, p. 58 (Carolines); idem, Novit. Zool., 7, 1900, p. 3 (Ruk); Seale (part), Occ. Papers Bernice P. Bishop Mus., 1, 1901, p. 53 (Ponapé); Matschie, Journ. f. Ornith., 1900, pp. 112, 113 (Ruk, Ponapé, Ualan); Dubois, Syn. Avium, 1, 1902, p. 369 (Ponapé); Reichenow, Die Vögel, 2, 1914, p. 545 (Ponapé); Takatsukasa and Kuroda, Tori, 1, 1915, p. 54 (Ponapé, Ruk); Mayr, Proc. 6th Pacific Sci. Congr., 4, 1941, p. 204 (Ponapé).
Conopoderas syrinx Wetmore, in Townsend and Wetmore, Bull. Mus. Comp. Zoöl., 63, 1919, p. 214 (Ponapé, Truk); Takatsukasa and Yamashina, Dobotsu. Zasshi, 43, 1931, p. 485 (Caroline Is.); Yamashina, Tori, 7, 1932, p. 405 (Ponapé); Hand-list Japanese Birds, rev., 1932, p. 177 (Carolines).
Acrocephalus stentoreus syrinx Kuroda (part), in Momiyama, Birds Micronesia, 1922, p. 67 (Ruk, Ualan, Lugunor, Wolea, Nukuoro, Ponapé).
Conopoderas luscinia syrinx, Hand-list Japanese Birds, 3d ed., 1942, p. 197 (Wolea, Lamotrek, Truk, Lukunor, Nukuoro, Ponapé, Kusaie).
Acrocephalus luscinia syrinx Mayr, Birds Southwest Pacific, 1945, p. 294 (Carolines); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 67 (Truk).
Geographic range.—Micronesia: Caroline Islands—Woleai, Lamotrek, Truk, Lukunor, Nukuoro, Ponapé, Kusaie.
Characters.—Adult: Resembles A. l. luscinia, but smaller; with shorter, straighter bill; head and neck more reddish-brown; back, rump, wing, and tail edged with cinnamon; flight feathers faintly tipped with white.
Immature: Resembles adult, but lighter and more rufous in color; wings and rump paler, wings edged with rufous buff.
Measurements.—Measurements are listed in [table 37].
Specimens examined.—Total number, 62 (35 males, 20 females, 7 unsexed), as follows: Caroline Islands, USNM—Ponapé, 1 (Feb. 12)—Truk, 4 (Feb. 16, Mar. 15); AMNH—Ponapé, 35 (Nov., Dec.)—Truk, 22 (Feb., March, May, June, Nov.).
Nesting.—Birds nest in reedy swamps and scrub vegetation in the Caroline Islands, although Finsch (1881b:115), recording a field note by Kubary, states that nests were found in trees at Mortlock Atoll (= Lukunor). Yamashina (1932a:405) reports the collecting of seven sets of eggs at Ponapé in July and August, 1931. The sets consisted of one or two eggs each. McElroy of the NAMRU2 party obtained specimens with enlarged gonads at Truk in December and noted that birds were carrying nest materials to cane swamps. Of the birds secured by Coultas in November and December at Ponapé, only a small number had enlarged gonads. He also found nests containing no eggs in low bushes at Ponapé. Hartert (1900:3) reports that at Truk Owston's Japanese collectors obtained "many nests" from the end of May to the beginning of July. These nests contained one or two eggs and were found 7 to 20 feet above the ground in breadfruit, coconut and ivory-nut palm trees. Hartert writes, "The eggs are white, covered with darker and lighter brown patches, and underlying ashy grey or lavender-grey spots. These spots are generally thicker near the broad end, sometimes forming a loose ring, and they are sometimes equally spread over the whole surface." He lists measurements of 48 eggs.
Molt.—Of the specimens examined by me, those taken in the spring and summer are in fresh or worn plumage; those taken in fall and winter are in molt, with a few skins exhibiting worn or fresh plumage in the latter period. Apparently the peak in the molting process occurs from September to December.
Food habits.—The reed-warbler is an insect feeder. Coultas, in his observations of the bird at Ponapé, relates that he was able to locate the warbler by listening for the "snapping of the mandibles as the bird is catching food."
Remarks.—From the observations of Kittlitz, Kubary, Coultas, McElroy, and others, it is apparent that the Nightingale Reed-warbler in the Caroline Islands is restricted to the lower elevations of the islands. Whereas the reed-warbler at Guam seems closely associated with cane swamps and adjacent vegetation, the bird in the Carolines may range more extensively into brush lands, forest margin and grass lands. Coultas (field notes) notes that the reed-warbler at Ponapé is a "common bird of the small bush and grasslands. One is attracted by its warbler-like song. The bird spends hours perched on a stem of a bush caroling the time of day. When feeding, one finds it on the ground or working away quietly among the bushes. Acrocephalus is a friendly bird who does not become frightened easily. He responds to man-made calls."
The Nightingale Reed-warbler is found on many of the islands in the Caroline Chain, including both the "high" volcanic islands (Ponapé and Truk) and the "low" coral islands (Lukunor and Nukunor). Although the bird has been recorded at Kusaie by Kittlitz and Finsch, it was not taken there by Coultas in 1931. Reed-warblers are unknown at Yap, Ulithi, Fais or at other islands of the extreme western Carolines, or in the Palau Archipelago.
They are unrecorded also in the Marshall Islands, but at Nauru in the Gilbert Islands, to the southeast, an isolated population of this bird occurs and has been named A. l. rehsei (Finsch).