AYTHYA. 101 



Genus AYTHYA Boie. (Page 85, pi. XXIV., figs. 1-3.) 



Species. 



Common Characters. — Adult males with the head and part of the neck uni- 

 form chestnut or black, the lower neck uniform black (except in a few exotic 

 species) ; back and scapulars waved with white and black ; speculum bluish gray, 

 or white, tipped with black ; lower parts white. Adult females with head, neck, 

 chest, and upper parts plain brownish, the head paler or whitish next the bill ; 

 speculum as in the male. 



a 1 . Culmen longer than inner toe, with claw ; bill not wider near end than at base ; 

 head and neck reddish in adult males. 

 b 1 . Bill much shorter than middle toe without claw, its greatest width nearly 



half the length of the culmen, the end moderately depressed, and the 



nail decidedly hooked. (Subgenus Aythya.) 

 c 1 . Adult male : Head and upper half of neck rich chestnut-red, glossed 

 with reddish purple ; lower neck, chest, upper back, rump, and tail- 

 coverts (above and below) black ; back, scapulars, sides, and flanks 

 waved or vermiculated with white and black, in nearly equal pro- 

 portion ; belly immaculate white. Adult female : Head and neck 

 grayish brown, darker above, the fore part of the former lighter, 

 almost white on chin and upper throat; back, scapulars, chest, sides, 

 and flanks dull grayish brown, the feathers tipped with paler, or 

 fulvous. Downy young : Above ochraceous olive-brown, with an 

 indistinct yellowish spot behind each wing, another on the hind 

 border of the arm- wing, and a third on each side of the rump ; 

 whole sides of head and neck, with lower parts in general, deep 

 buff-yellow, paler and duller on belly and ventral region ; no dark 

 markings on side of head. Length 17.00-21.00, wing 8.50-9.25, 

 culmen 2.05-2.25, greatest width of bill .75-.85. Eggs 2.42 X 173, 

 pale olive-buff or pale dull greenish buff. Sab. "Whole of North 

 America, breeding from Maine and California northward. 



146. A. americana (Eyt.). Redhead. 

 c\ Adult male: Head and whole neck chestnut-rufous, without distinct 

 purple gloss ; back, scapulars, and whole lower parts, except chest 

 and under tail-coverts, white, everywhere finely waved or vermic- 

 ulated with dusky; otherwise like A. americana, but upper man- 

 dible (in life) pale blue only between nostril and end, the basal por- 

 tion being dusky. Adult female : Differing from the same sex of 

 A. americana chiefly in the color of the bill (hardly appreciable in 

 dried specimens) and in the different proportions. Wing 8.00-8.50, 

 culmen 2.20-2.40, greatest width of bill .70-.78. Sab. Europe, with 

 portions of Africa and Asia. A. fe rina (Liuk.). Pochard. 1 



i Anas ferina Link., S. N. ed. 10, i. 1758, 126. Aythya ferina Boie, Isis, 1822, 564. 



