Vol. XXXIl 



1914^ J DwiGHT, Plumages of the Scoters. 307 



Oidemia nigra and Oidemia fusca. 



It would be folly for me with the limited material I have examined 

 to attempt to follow, as I have done with the three American 

 species, the moults and plumages of these foreign species, but for- 

 tunately we may turn for this to J. G. Millais' "British Diving 

 Ducks," 1913. In this splendid work will be found the best 

 accounts yet published of the moulting of certain ducks and I agree 

 with almost all of the views expressed therein regarding Scoters. 

 Still, I regard the term "immature" as too vague to cover the situa- 

 tion satisfactorih' and I find no mention is made of the prenuptial 

 moult of adults, nor of the emarginate primary of nigra, while the 

 occurrence of an "eclipse" is claimed for nigra, fusca and even 

 perspicillata. 1 will quote Mr. Millias' own words regarding the 

 "eclipse" in the Velvet-Scoter (fusca). 



"The most interesting feature, however, is a patch of whitish brown 

 echpse feathers behind the eye and the bill which had evidently come in in 

 July and give the bird a female appearance. In front of these feathers is a 

 jet black patch which has, however, only been renewed once in the plumage 

 change (July-November) . The breast and lower parts are brown and the 

 tail and wings are being renewed. The bird was incapable of flight when 

 I shot it." 



His photographic plate of the bird shows a dorsal view with the 

 head turned to one side and without actually having the specimen 

 in hand I must say that the "eclipse" feathers look suspiciously 

 like worn feathers of an earlier plumage and probably were ac- 

 quired at the prenuptial moult. Such feathers frequently persist 

 on these (and other) areas and I have a specimen of the closely 

 related dcglandi (Am. Mus. No. 119176 cf ad., June 2, Mackenzie 

 River delta) which matches the one in question very nearly, new 

 black, growing among the brownish feathers near the bill. I con- 

 sider my bird as beginning the postnuptial moult, for the flight 

 feathers and tail are old and there are comparatively few evidences 

 of moult elsewhere. Specimens of perspicillata and americana 

 show no signs whatever of "eclipse" in July, August or September, 

 although some birds are browner than others about the head, 

 which is merely individual variation. The feathers of perspicillata 



