430 



Key to Plate No. 21 Plate No. 21 - 



AUTUMN PLUMAGES 



(A) RING-NECKED DUCK, adult male in early stage of autumn moult. 



(B) RING-NECKED DUCK, adult male in later stage of autumn moult. 



(C) AMERICAN GOLDEN-EYE, adult male during autumn moult. 



(D) BARROW'S GOLDEN-EYE, adult male during autumn moult. 



(E) BUFFLE-HEAD, adult male during autumn moult. 



(F) HARLEQUIN DUCK, adult male during autumn moult. 

 Note : During autumn moult the wing is as in winter plumage. 



EXPLANATION OF THE AUTUMN MOULT 



During autumn, the males of the ducks are moulting out of the "eclipse" 

 plumage, which closely resembles that of the female, into the full winter plumage 

 of the drake. A careful examination of the plumage characters will disclose 

 some indications of the male winter dress slight in the early autumn but pro- 

 gressively increasing as the season advances. The full range of the moult will 

 be best appreciated if the plates showing the female plumage and that of the 

 male in winter are examined at the same time as this plate. 



Young males of the year follow much the same sequence of moult out of the 

 juvenile plumage (which also resembles that of the female) and are similar to 

 adult males during the autumn moult, except for the wings, which differ as stated 

 in "Description" of Juvenile in the text. 



Consult "Specimen Identification" in the text, and section on "Identifica- 

 tion of a Specimen in Hand." 



Winter plumages : 



Ring-necked Duck and Buffle-head, Plate No. 18. 

 American and Barrow's Golden-eye, Plate No. 20. 

 Harlequin Duck, Plate No. 23. 



Text: Ring-necked Duck, page 236; American Golden-eye, page 259; 

 Barrow's Golden-eye, page 269; Buffle-head, page 273; Eastern 

 Harlequin Duck, page 287; Western Harlequin Duck, page 292. 



