42 BULLETIN 130, UNITED STATES NATIONAL MUSEUM 



edged with '' sayal brown" and the rest of the head, neck, breast, 

 back and wings are deep, rich " seal brown," nearly black on the up- 

 per surfaces) before they migrate north in the spring; I have seen 

 birds in the full perfection of this plumage as early as May 10 ; but 

 most birds reach their breeding grounds in various stages of transi- 

 tion, showing more or less white or gray feathers in the dark areas. 

 There is no real eclipse plumage in the oldsquaw, but Mr. Millais 

 (1913) says: 



During August the male long-tailed duck completely changes the wing, tail, 

 back, and black portion of the mantle and black breast band, these parts being 

 replaced by the new winter plumage. The head, neck, and upper mantle, show- 

 ing worn and faded plumage feathers, remain until shed at the end of Sep- 

 tember. The elongated scapulars are shed and not renewed until late Sep- 

 tember, but in late July a considerable number of new blackish and brown 

 feathers come into the upper scapulars and mix with the old worn summer 

 plumage feathers, whilst a number of new dark-gray feathers, similar to those 

 worn by the scaup, tufted duck, and goldeneye male in eclipse, come unto the 

 flanks and remain until shed again in early October. The reason of this, I 

 take it, is that since Nature abhors sudden changes of color from dark to 

 light, whilst the landscape is still under the warm colors of summer and 

 autumn, the male long-tail only renews those parts of its plumage to the full 

 winter dress which are directly in harmony with its surroundings, adding, 

 however, temporary feathers, as it were, to carry it over the three temperate 

 months wlien it hides in the shadows of banks or rocky inlets. Thus all the 

 dark parts of its plumage are renewed once, and once only, and the light parts 

 which would be noticeable are delayed by a temporary makeshift until such a 

 time as concealment is no longer necessary. • 



Of the plumage changes of the female he saj^s : 



In first plumage the immature female closely resembles the young male, ex- 

 cept that the color is somewhat paler. They are also easily recognized by 

 October by the incoming feathers of the respective sexes. In the case of the 

 young female the advance of plumage is somewhat slower than that of the 

 male, and she only obtains a few of the winter dress feathers. In April the 

 greater part of the adult summer plumage is assumed, but there is little or no 

 change on the back, breast, and lower parts, whilst tire wings and tail are not 

 shed at all until the principal molt in July and August. The young female 

 then gradually assumes her winter dress, which is complete in October. She is 

 thus adult at 16 months, and will pair and breed the following summer. 



Young females may be recognized during their first year by their 

 imperfect and more or less mottled head pattern and by the broad, 

 gray edgings of the upper back and scapulars. Adult females in 

 winter have the feathers of the back, scapidars, and wing coverts 

 broadly edged with '^ tawny " or " cinnamon brown," and the upper 

 chest and flanks are suffused with lighter shades of the same. The 

 partial prenuptial molt occurs in April, leaving the wings worn and 

 faded ; the head becomes largely brownish black, with whitish spaces 

 before and behind the eye, and the upper parts are nearly uniform 

 brownish black. In August and September a complete molt pro- 

 duces the Avinter plumage. 



