72 KEY TO THE BIRDS OF EASTERN NORTH AMERICA. 



Head, greenish purple, no white on head; back, dull black; speculum, gray (male). 



Aythya collar/*. Ring=neck Duck. 



See No. 107. 



Head, dull brown, brownish white at base of bill and below eye; speculum, gray 

 (female). Aythya collaris. Ring=neck Duck. 



See No. 107. 

 Head, greenish purple, a large patch of white on back of head (male). 



Charitonetta albeola. Buffle= headed Duck. 



See No. 110. 



Head, dark brown or dusky, a patch of white behind the eye (on ear coverts) ; no 

 white or brownish white at base of bill; speculum, white (female). 



Charitonetta albeola. B uf f I e= headed Duck. 

 See No. 110. 



Section 2. Belly, not white. 



Plumage, variously marked with white, slate-color, and chestnut (male). 



Histrionicus histrionicus. Harlequin Duck. 



See No. 112. 

 General plumage, dull brown, mottled on the under parts (female). 



Histrionicus histrionicvs. Harlequin Duck. 



See No. 112. 

 Head, mostly white, greenish on lores and occiput (male). 



Eniconetta stelleri. Stellers' Duck. 



See No. 114. 

 Head, light brown; belly, clear, sooty brown (female). 



Eniconetta stelleri. Stellers' Duck. 

 See No. 114. 



* Group 3. Wing, from 7.50 to 8.50 inches long. 



Section 1. Head, marked with more or less white or 

 brownish white; belly, white, sometimes tinged with 

 dusky or gray on lower part. 



Head, brownish ; a patch of dull white on face at base 

 of bill; speculum, white (female). 



Aythya marila. Greater Scaup Duck. Blue-bill. 



See No. 105. 



Aythya marila nearctica. 



Speculum, ichite, similar to preceding but somewhat smaller (female). More common in 

 the South than the Greater Scaup Duck. Aythya affinis. Lesser Scaup Duck. 



See No. 106. 



* For directions for measurement, see page 9. 



