108 SEA DUCKS. 



bill, as in the Anatince, acts as a sieve or strainer. As a rule they feed 

 by day and pass the night at a distance from the shore or at sea. Some 

 of the species occur in our waters in large flocks — indeed, our most 

 abundant Ducks are members of this subfamily. With one exception 

 they are northern breeding birds, seldom nesting south of our north- 

 ern tier of States. 



Their nest is composed of twigs, loaves, grasses, stems of aquatic 

 plants, seaweed, etc., lined with down from the breast of the incubat- 

 ing bird. 



KEY TO THE aPEOIES. 



I. Feathers at the base of the bill not reaching -50 forward along its sides. 

 A. Wing over 7'00 ; axillars and most if not all the linings of the wings white. 



a. Head and neck black, with greenish or purplish reflections. 

 «!. Back black ; bill with a bluish band near its tip. 



150. KiNG-NECKED DuCK $. 



Ji. Back finely barred with black and white. 

 M. Back of head generally with purplish reflections ; wing generally 

 under 8'25 ; nail of bill generally under •25 in width. 



149. Lessee Scaup Duck 3. 

 53. Back of head generally with greenish reflections; wing gener 

 ally over 8'25 ; nail of bill over -25 in width. 



148. Am. Scaup Duck &. 



b. Head and neck rufous or rufous-brown, sharply defined from the black 

 breast. 



61. Head and upper neck rich rufous ; bill 2-00 or under ; flanks finely 

 barred, like the back 146. Eedhead s , 



f. Head and neck rufous-brown ; crown blackish ; bill over 2-00 ; flanks 

 very slightly if at all barred 147. Canvasback i . 



c. Head and neck brownish or grayish, 

 e'. A white patch in the wing. 



c". Feathers at ba.se of bill white ; wing generally under 8'25 : nail of 



bill generally under '25 in width . . 149. Lessee Scaup Duck 9 , 



cs. Feathers at base of bill white ; wing generally over 8-25 ; nail of 



bill generally over '25 in width . . . 148. Am. Scaup Duck 9- 



d^. No white in wing. 



(P. An indistinct bluish hand near the tip of bill ; bill under 2-00. 



d^. Wing under 8-00 150. Eino-mecked Duck 9 . 



d'. Wing over 8-00 146. Eedhead 9 . 



«2. No band on bill ; bill over 2-00 147. Canvasback 9.' 



Ji. Wing over 7'00 ; axillars and most if not all the under wing-coverts 

 blackish. 



a. Head and throat dark steel-blue or steel-green, 

 a'. Head and throat steel-blue ; white patch at base of bill 1-00 or more 



in height 152. Barrow's Golden-eye a . 



a'. Head and throat steel-green ; white patch at base of bill less than 

 1-00 in height 151.. Am. Golden-eye a. 



