(2266) Anas poecilorhyncha zonorhyncha.
The Eastern Grey Duck.
Anas zonorhyncha Swinhoe, Ibis, 1866, p. 394 (Ningpo, China).
Vernacular names. Taw-be (Burma).
Description. Differs from the preceding bird in never having red spots at the base of the bill and in having the speculum blue and not green as it is in that bird; the white on the outer secondaries is much less in extent, sometimes absent altogether; generally in the Eastern Grey Duck the chin and throat are a purer white and contrast more strongly with the rest of the underparts, which are darker; the white supercilium seems more conspicuous in the Eastern than in the Western bird.
Colours of soft parts the same as in the preceding bird but with no red spots at the base of the bill.
Measurements a little smaller than in the Indian Grey Duck. Wing, 254 to 276 mm., 243 to 260 mm.; culmen 56 to 63 mm.
Distribution. Transbaikalia, Eastern Siberia and Mongolia to Japan (Yezzo and Riu-kiu) and Northern China. In Winter this duck moves South to Cochin China, Yunnan and South China. There is one specimen from Kentung, Southern Shan States, in the British Museum collection, whilst Harington also shot one at Taungyi, Burma, in December 1911.
Nidification. Styan and La Touche record these ducks as breeding in Foochow and on the Yangtse in May, June and July, making their nests in the low bushes and rank grasses in which they were well hidden. In Japan they breed from April to July, making, according to Owston, a fairly compact and well-built nest like that of the Mallard, well lined with down. They seem to lay six to ten eggs, which are indistinguishable from those of the Indian Grey Duck. Forty-four eggs average 55.5 x 41.6 mm.: maxima 57.3 X 41.0 and 55.5 x 43.6 mm.; minima 51.1 x 39.7 mm.
Habits. Similar to those of the other Grey Ducks except for the fact that it is truly migratory and that it haunts sea-coasts as well as inland waters. According to Gee and Moffatt the Eastern Grey Duck is easily domesticated and interbreeds freely with the domestic duck.