168 INDIAN UUCKS 



(26) ANAS PffiCILORHYNCHA ZONORHYNCHA. 



THE EASTERN GREY DUCK. 



Anas zonorhyncha, SinnJior, Ilns, 186(), p. 394 (Ningpo) ; Sahridoii, Cat. 

 B. M. xxvii, p. 211 ; ' Asian,' Jan. 10, 1899 : Stuart Baker, 

 J. B. N. H. S. xvi, p. 12 : Oates. Game-B. ii, p. 148 ; Stuart Baker, 

 Indian Ducks, p. 140 (1908) ; Harhujton, J. B. N. H. S. xxi, p. 1086 

 (1912). 



Description. — Tlie eastern form of the Grey Duck differs from the Indian 

 Spot-Bill in not having at any period of its life the two red spots at the base 

 of tlie upper mandible, and in having the speculum blue, and not gi'een as it 

 is in that bird. Also the outer secondaries have far less white upon them — 

 indeed, in some birds this is almost absent. The following differences are 

 also noticeable in comparing series of the two ducks : in the eastern form 

 the chin, throat, and fore-neck are conspicuously white, and contrast strongly 

 with the rest of the underparts, which are far darker than in the western 

 bird. In both, the under tail-coverts are very dark brown, but whereas in 

 zonorhyncha these are almost concolorous with the feathers of the vent and 

 lower abdomen, in pa'cilurhyncha the abdomen is much lighter, and contrasts 

 distinctly. In the latter the underparts are generally very much spotted, 

 the spots increasing with age, in the former the spots are nearly or quite 

 obsolete. In the Eastern Grey Duck the white of the supercilium is also 

 much purer and better defined than in the Western Grey Duck. The soft 

 parts, with tlie exception of there being no spots at the base of the bill, are 

 the same as in the other Grey Duck. 



Measurements. The bill averages smaller. In the series of pa'cilolujn- 

 cha in the British Museum there are females with bills up to 2'20 inches, 

 and males up to 2'38 straight along the culmen from tip to feathering on the 

 forehead. 



The largest male of zoiwrlujnclia has the bill only 2'2.5 inches, and the 

 next liiggost bird, unsexed, has it 2'20. The largest sexed female has it r98. 



The average wing measurement for both sexes is 10'71 inches, and of the 

 l)ill 207. 



Distribution. — Trans-Baikalia, Eastern Siberia and Mongolia to 

 Japan (Yezzo and Riu-kiii) and Northern China. In winter south to 

 China, Cochin China and Yunnan. There is a typical specimen 

 recorded from Kengtung in the Shau States, and Hariugton also 



