108 SEA DUCKS. 



bill, as in the Anafinw, 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. \Viili one exception 

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

 ern tier of States. 



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

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

 ing bird. 



KEY TO TI1K SPECIES. 



I. Feathers at the base of the bill not reaching -50 forward along ita side -s. 



A. Wing over T'O" ; uxillars and most if not all the linings of the wings white. 



a. lli'!i< 1 uii'l neck black, with greenish or purplish ivllivt'n'iis. 

 a 1 . Buek black; bill with a bluish bund near it* tip. 



150. KINO-NECKED DUCK S . 

 b*. Back finely barred with black and white. 



I*. Back of head generally with purplish reflections; wing generally 

 under >_'." ; nail of bill generally undi-r "jr. in width. 



149. Li ssi i: s, ATP DUCK S . 



b*. Back of head gi-nrrally with greenish reflections; wing gnu-r- 

 ally over 8'2.">; nail of bill over "l~> in width. 



148. AM. SCAUP DUCK ,? . 



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

 breast 



b 1 . Head and upper neck rich rufous; bill 2-00 or under; flanks finely 

 barred, like the back 140. REDHEAD S . 



b*. Head and neck rufous-brown ; crown blackish ; bill over -J-Oo ; Hanks 

 very slightly if at all barred 147. CANVASBACK 6 . 



c. Head and neck brownish or grayish. 

 c l . A white patch in the win-,'. 



t*. Feathers at base of bill white; wing generally under S-25: nail of 



bill generally under --2't in width . . 149. LI>SKI: SI-ATI- DTCK 9. 

 c*. Feathers at base of bill white; wing irenerally over VL'.">; nail of 



bill generally over _'.") in width . . . 14S. AM. SCAUP DUCK 9 

 d l . No white in winir. 

 d*. An indistinct bluish band near the tip of bill; bill under 2-00. 



d*. Wing under 8-00 150. RIXO-NK-KKI> I>T<K 9. 



d*. Wing over 8-00 14 15. UKDIIEAD 9 . 



<*. No band on bill ; bill over 2-oO 1 17. CANVASI-.ACK 9.. 



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

 blackish. 



a. Head and throat dark steel-blue or steel -^n-eu. 



a 1 . Head and throat steel-blue; white i>at<-h at base of bill 1-00 or more 



in height !;">-. BAXBOW'C Qou>rar-BYB i . 



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



I'OO in height 151. AM. GOLUEN-EVE 6. 



