'^^^ioif'^''] DwiGHT, Plumages of the Scoters. 299 



wing-quills are just showing with the down still adherent at their 

 apices. The tail is grown and much worn illustrating the fact that 

 in the duck, a water fowl, the tail develops earlier than do the 

 flight feathers which is contrary to the order of moult in land birds. 

 The scapulars and breast feathers are partly gro\\Ti. 



Juvenal Plumage (Plate XXVIII, Fig. 1), acquired by a com- 

 plete post natal moult, and in this dress the sexes are alike although 

 females average a little smaller in most of their measurements. 

 It is unsafe without dissection to attempt to distinguish the sexes 

 until feathers of the first winter plumage begin to appear together 

 with the later changes in the color and form of the bill in the male. 

 Young males arriving from the north in October (J. D., Jr., No. 

 9798, Oct. 26) and in early November (J. D., Jr., No. 4716, Nov. 8) 

 soon begin to show a scattered growth of black feathers and later 

 the females show brown feathers but the juvenal dress may be worn 

 in some cases for several months before the postjuvenal moult sets 

 in. A spring female (J. D., Jr., No. 4867, March 4), for example, 

 is wholly in juvenal plumage with merely a few new feathers be- 

 gining to appear. 0. nigra and americana are practically alike in 

 this plumage, being brown above with a dark cap and lighter below, 

 but the bill of 7iigra is rather heavier; deglandi, carho, fusca and 

 perspicillata are brown above, lighter below and show two large 

 white spots on the side of the head, and deglandi, carho, and fusca 

 have white wing patches. 



1st Winter Plumage (Plate XXVIII, Figs. 2 and 3), acquired by a 

 partial postjuvenal moult which never includes the wings and 

 seldom the lower surface of the body. At most the head, neck, 

 back and sides become black in males and a much less extensive 

 growth of brown feathers occurring relatively later takes place in 

 females. The tail too is moulted, the rectrices showing irregulari- 

 ties in their replacement. The moult probably progresses slowly 

 but it must be remembered that in the winter while we see individ- 

 uals in all stages no doubt they begin to moult at widely different 

 dates and it is impossible to say just how long any one bird has 

 been actually moulting. I am convinced that males which are well 

 advanced by January, also undergo a prenuptial moult in April 

 or May, like adults, but it is difficult to tell whether the specimens 

 which are moulting at this late period are undergoing a much 



