300 BUCEPHALA CLANGULA 



DESCRIPTION 



Adult Male: Head and upper neck dark metallic green, purplish in certain lights. Between the base 

 of the bill and the eye a large rounded white patch. Lower neck, breast and abdomen pure white, 

 except for a few grayish feathers about the thighs and vent. Flanks with a few long feathers mar- 

 gined with black. Under tail-coverts white. Anterior part of the mantle white, posterior part black 

 merging with the black of the central scapulars, back, rump and tail. Outer scapulars white, or white 

 with black borders. Wing black, with a large white patch on the central coverts and the inner sec- 

 ondaries. Primaries dark brown. 



Iris golden yellow. Bill black or blue-black. Legs and feet orange, brighter in spring; webs grayish. 



Wing 216-231 mm.; bill 33-41; tarsus 35-41. 



Weight 2 pounds, 6 ounces to 2 pounds, 10 ounces (1.07 to 1.19 kilograms). 



Adult Female: Head and upper neck hair brown, changing rather abruptly into a broad collar, 

 which is w T hitish below and grayish above. Mantle and scapulars dark slate gray, the margins of the 

 feathers being lighter in color. Back, rump and tail almost black. Upper breast pale gray; lower 

 breast and whole abdomen pure white. Sides and flanks pale gray. Under tail-coverts white. Wing 

 dark gray, but the median coverts are broadly tipped with white, and the greater ones are white, 

 tipped with black. Outer secondaries white, primaries dark brown to black. Under wing grayish 

 white. 



Iris golden yellow. Bill bluish black; but in breeding season bright yellow at the tip. Legs and feet 

 yellow or orange yellow, with the webs blackish. 



Wing 190-216 mm.; bill 28-35; tarsus 33-36. 



Weight 2 pounds to 2 pounds, 8 ounces (0.90 to 1.13 kilograms). 



Female in First (Juvenal) Plumage: At first the head is paler than in the adult female and the 

 white collar is entirely absent. The whole upper side, as well as the upper breast is brownish rather 

 than grayish, and the tips of the tail-feathers are more or less blunted. The bill lacks the yellow spot 

 at the tip and is dark olive color as a rule. 



Young Male in First (Juvenal) Plumage : In August and September it may be impossible to tell 

 the sexes of young birds except by the greater size of the male. Beginning, however, in October 

 some young males of the year have a few dark feathers coming in on the sides of the head and neck or 

 around the area which is to form the white face-patch. The whole head as well as the back and rump 

 may be richer and darker than in the young female. About the same time a few white feathers may 

 usually be found among the scapulars. The white face-patch appears in some cases by mid-October, 

 but in others not before March. Progress toward maturity is very slow and many males looking es- 

 sentially like females are found all through the winter. 



Weight 2 pounds, 2 ounces to 2 pounds, 4 ounces (0.96 to 1.02 kilograms). 



Immature Male: During February, March and April the appearance of the young male changes 

 more rapidly, and while the scapulars assume the whiteness of maturity the head becomes much 

 darker and the neck-collar lighter. But adult plumage is not assumed the first year. Probably few 

 males are in perfect feather before nineteen or twenty months of age. 



Male in Eclipse: I have not seen what I should consider a full-eclipse specimen, but old males with 

 somewhat delayed plumage taken in October give a good picture of what this must be. The head 

 becomes mostly brown, retaining some green on the occiput, and the white face-patch disappears. 

 The lower neck, mantle and upper breast become gray, perhaps mixed with some white feathers, and 

 the inner scapulars, back, and rump become more brownish, the former having light edges to the 



