AMERICAN EIDER 303 



plumage commences in late June and reaches its climax in late July or August. 

 In this plumage the bright colours of head and neck are replaced by blacks and 

 browns, feathers of the back are greyish, tipped with dusky, and the chest be- 

 comes barred with black and brown. The full-plumaged wing is renewed. 



AUTUMN PLUMAGE: In early autumn the adult male commences a moult out of 

 the eclipse plumage, described above, into full winter plumage. In early stages, 

 a scattering of new, white feathers may be seen on head, neck, back, and scapulars; 

 the chest also shows a few white feathers of winter plumage among brown-and- 

 black barred ones of the eclipse. Later, the black-and-white head pattern of the 

 winter plumage becomes recognizable, and a few sea-green feathers appear on the 

 hindhead, though they are still mixed with a number of old brownish eclipse- 

 feathers; the back, scapulars and chest are mostly white, with a few, old brown 

 feathers. The moult usually continues till late December, when full winter plumage 

 has been attained. Throughout this moult the full-plumaged wing distinguishes 

 the fully adult male from younger males. 



ADULT FEMALE. Head and neck, brown, finely streaked with black, darker 

 on crown; bill, duller and greener than that of male in winter; nail, bone yellow; 

 bill-processes, same as those of male but narrower posteriorly; eye, dark brown. 

 Body. Back and scapular feathers, brownish black, broadly tipped, barred and 

 mottled with rusty brown and buff; chest and sides, feathers brownish buff, barred 

 with blackish and tipped with greyish buff; breast and belly, dusky brown; feet, 

 greyish yellow, webs dusky. Tail, greyish brown; upper and under coverts, like the 

 back. Wings. Lesser and middle coverts, like the back; greater coverts, greyish brown, 

 tipped with white; primaries, brownish black; outer secondaries, brownish black, 

 tipped with white; inner secondaries and tertials, rusty brown on outer web, brown- 

 ish black on inner web; lining, brownish grey and white; axillars, whitish. 



JUVENILE. In the first autumn the sexes are much alike but do not, as is 

 the case with most ducks, resemble the adult female. The plumage is dull brown, 

 with narrow sandy-brown edges to the feathers. The young male has a larger 

 eye-stripe, darker upperparts and paler chest than the young female. During late 

 autumn the young male differentiates by acquiring some black feathers in sides 

 and scapulars, and some white feathers in chest. This moult continues during the 

 winter, and by April many young males have the throat, neck and chest almost 

 wholly white; the sea-green patch around the ear region is either completely 

 developed or mixed with black and brown feathers; the wing and underparts are 

 still immature. 



During July and August of the second summer the first eclipse moult takes 

 place. This is a complete double body-moult, and the first winter plumage is re- 

 placed by another which is similar but darker. During the second autumn a moult 

 towards adult plumage continues and usually by November the plumage resembles 

 that of the adult, but the young male can be recognized by certain imperfections: 

 the crown is mottled with greyish brown; the white back shows a sprinkling of 

 dusky feathers; the breast, black in the adult, is dull brownish-black, mottled and 

 broken where it meets the white of the forebreast and chest. This plumage is worn 

 until the second eclipse moult takes place; further progress towards full dress is 

 made, and, after the third eclipse moult the plumage is fully adult, though there 

 may be considerable individual variation as to this period. 



The young female retains the immature plumage during the first winter, 

 but by March most of the birds have acquired a semi-adult plumage but can be 



