Vol. XXXIl 



1914 



] DwiGHT, Plumages of the Scoters. 301 



rule the moult is almost completed when the birds reach our lati- 

 tude. At this time the characteristic emarginate distal primary 

 is assumed replacing the uncut juvenal feather (Plate XXV) 

 and the yellow hump of the bill has in some cases reached full 

 development. The plumage is now wholly black. As early as 

 October 26 (J. D., Jr., No. 9796) I have seen a specimen that had 

 ceased to show any signs of moult while others as late as November 

 12 (J. D., Jr., No. 11983) still show a few pin feathers growing on 

 several of the feather tracts. There is a difference in the intensity 

 of the black in fall specimens and we may suppose the blackest are 

 birds several years old although it is probable that individual 

 variation is the real factor. At all events, the duller birds are the 

 ones that in the course of the winter show the most wear and 

 become more or less brown in the second spring. It may be noted 

 that the growth of the hump of the bill tilts the nostril from the 

 more horizontal position it has in the young male. The nostrils 

 of dcglandi and perspiciUata being wholly within the zone of the 

 uplift do not lose their relative positions. 



Sd Nuptial Plumage (and all later nuptial plumages) acquired by 

 a partial prenuptial moult involving the body feathers and the tail. 

 Contrary to general opinion an extensive moult takes place at this 

 period in both sexes. No birds of many examined in March and 

 April fail to show abundant growth of new feathers. As these, 

 however, are black like the old ones they replace, no change in the 

 appearance of birds is affected save that the plumages look fresh 

 and new. 



3d Winter plumage (and all later winter plumages) (Plate XXVIII, 

 Fig. 4, cf ; Fig. 5, 9 ) acquired by a complete second postnuptial 

 moult. Differs only from the first postnuptial plumage in that a 

 black emarginate primary replaces a similar one instead of replacing 

 a plain brown juvenal feather as at the first postnuptial moult. A 

 large part of the variation in intensity of color in plumage, bills and 

 feet is probably in consequence of some adults being only one year 

 old while others are two or more. The adult female is uniformly 

 dark brown above and below, whereas the juvenal female is much 

 lighter below and shows a more distinct cap. 



