(797) Acrocephalus arundinaceus orientalis.
The Eastern Great Reed-Warbler.
Salicaria turdina orientals Temm. & Schleg., Fauna Jap., Aves..p. 50 (1847) (Japan). Acrocephalus orientalis. Blanf. & Oates, l, p. 357.
Vernacular names. None recorded.
Description. Differs from A. s. brunnescens in having the second primary equal to, or longer than, the fourth. It is also slightly browner below and nearly always more heavily streaked on the breast.
From typical arundinaceus it differs in being darker above, much less fulvous below and in having the breast darker and more freely streaked.
Colours of soft parts. Iris brown; bill horny-brown or nearly black above, pale yellowish-horny below; legs yellowish brown, dark fleshy-brown or plumbeous-horny.
Measurements. Wing 79 to 83 mm.; tail 72 to 78 mm.; culmen 17.5 to 19.5 mm; tarsus about 30 mm.
Distribution. This Reed-Warbler breeds in Japan, Eastern Siberia and Northern China and in Winter is found throughout Southern China, the Indo-Chinese countries, Annam, Siam,. practically the whole of Burma to Assam.
Nidification. So far the Eastern Great Reed-Warbler has never been found breeding within our limits, nor is it likely that it ever will be. It is said by McGregor to be resident and breeding in the Philippines but this bird is a smaller form than the Northern migratory bird and will have to be separated. It breeds freely in Japan and Ricketts, La Touche and others have taken nests and eggs in various parts of Northern China. These are not distinguishable from those of A. s. stentoreus. One hundred eggs average 21.8 x 15.7 mm.: the maxima are 23.4 x 15.4 and 20.8 x 17.0 mm.; the minima are 19.4 X 15.4 and 19.0 x 14.3 mm.
According to La Touche eggs are to be found in Chinkiang from the middle of May to the middle of June and the number of eggs in a full clutch varies from three to five. In Japan they lay in May and June and the eggs number four to six.
Habits. Those of the genus.