Mayr examined seven specimens from Pagan in the Paris Museum. His measurements are: five males—wing, 76-79; tail, 66-69; bill from nostril, 14-14.5; two females—wing, 75, 77; tail, 66, 67; bill from nostril, 14.5, 15.
Remarks.—No specimens have been examined by me. Oustalet (1895:210) was the first to note the difference between the reed-warblers from Pagan and those from Guam and Saipan (A. l. luscinia). He regarded those from Pagan as similar to the population in the Carolines, calling them Tatare syrinx. Hartert, Seale, and Momiyama followed Oustalet in this regard, and it was not until 1931 that the population at Pagan was recognized as distinct, when further collections were made by the Japanese.
Acrocephalus luscinia nijoi (Yamashina)
Nightingale Reed-warbler
Conopoderas luscinia nijoi Yamashina, Tori, 10, 1940, p. 674. (Type locality, Agiguan.)
Conopoderas luscinia nijoi Hand-list Japanese Birds, 3d ed., 1942, p. 196 (Agiguan).
Acrocephalus luscinia luscinia Mayr (part), Birds Southwest Pacific, 1945, p. 294 (Agiguan).
Geographic range.—Micronesia: Mariana Islands—Agiguan.
Characters.—Adult: Resembles A. l. luscinia, but with shorter bill. Yamashina (1940:674) describes the birds as, "upper parts much less rusty in colour and the flanks and bellies are darker and more brownish than those of the specimens from Almagan and Saipan."
Measurements.—Yamashina (1940:674) gives the measurements of five adult birds from Agiguan as: exposed culmen 27-29, bill from nostril 17.0-20.0; as compared with 27 adult birds from Almagan and Saipan as: exposed culmen 30-34, bill from nostril 21.2-24.5.