VOL. IX.] MOULTS IN BRITISH DUCKS. 39 



it A\ill be seen that while first winter birds of some of 

 the species are ahnost indistinguishable from the adults, 

 others are differentiated by their wing-coverts which 

 are of the juvenile plumage, e.g. Gadwall, Wigeon, etc. 

 The following is a brief summary of the moults and 

 sequence of plumages in the 



Surface-feeding Ducks. 



Adult male. Winter. — This plumage is acquired by a 

 complete body- and tail-moult, and the innermost secondaries 

 are also moulted, but not the rest of the wings (unless the 

 inner secondary coverts are moulted, but I have seen no 

 specimen showing this). The moult may commence at 

 the end of July or in August (Mallard and Wigeon) or later 

 (Pintail) and maj^ be completed as early as the end of 

 September or beginning of October (Mallard) but often not 

 till November (Wigeon) or even later. 



Adult male. Smnmer. — No general moult, but body- 

 feathers here and there may be renewed (exceptions, Gadwall, 

 Shoveler and others previously mentioned, see p. 37). 

 Plumage as in winter but in some specimens very abraded. 



Adult male. Eclipse. — ^This plumage is acquired by an 

 apparently complete body-moult and by a complete wing- 

 moult, while in Mallard, Wigeon, Pintail and possibly in 

 other species the central pair of tail-feathers (in the Mallard 

 usually the two central pairs) are moulted and replaced, in 

 the Mallard by uncurled sepia feathers, in the Wigeon by shorter 

 less-pointed feathers, and in the Pintail by mouse-grey feathers 

 slightly pointed but not extending more than about one and a 

 half inches beyond the next pair of tail-feathers.* The other 

 tail-feathers are not moulted imtil the commencement of 

 the next moult, but occasionally a pair or two may be found 

 in quill before the appearance of the first winter feathers. 

 The wings may be shed at the commencement of the moult 

 into eclipse or towards the end of the moult and may still 

 be in quill at the commencement of the following moult 

 into the winter-plumage. The male in eclipse is usually 

 described as resembling the adult female, but this statement 

 is not applicable to all the species, and the eclipse plumage 



* j\Ir. Millais states in British Dicing Ducks (Vol. I. page 3) that the 

 central tail-feathers in the Mallard only moult once a year, whereas as 

 shown above they moult twice a year. This misconception of the 

 moults has, it would appear, led Mr. Millais to believe that these 

 feathers actually change colour. 



