56 



DUCKS, GEESJ: and swans of north AMERICA. 



AYTHYA HARILA NEARCTICA Stejn. 

 American Scaup Duck. 



BLLJU-Hir.L. Bl.ACK-IIEAD. 



Adxdt iiuik' : Head and neck and upper brea.st, black, showing greenish reflections ; back, 

 grayisli wliite, delicatelj^ Uued witli tine, wavy lines of black, giving it a grayish appearance; 

 speculum, white; under parts, white, the lower Ijelly showing grayish tinge. 



Length, 19; wing, 8. .50; tarsus, 1.50; bill, 2. 



-UiuU female: Patch at the base of the bill, white or gi-ayish white; rest of the head and 

 neck, breast, and upper back, l)rowuish; bellj^, white; speculum, white. 



Length, 17.75; wing, 8.25; tarsus, 1.30; bill, 1.6U. 



Aythyii mariUi iiuarctira (male). 



(t'laiuilu.) 



This s))ecic'S cjcctirs throughout North America, breeding north of the 

 United States. Jt ranges in winter south to the Bahama Islands and Guate- 

 mala, although it is not nearly as abundant in Southern waters as A. in. 

 affivis, to which it is very closely allied. Tiiere are, apparently, no constant 

 characters (with the possible exception of size) by which it may ))e sei)arated 

 from tiiat species ; the head, as a rule, shows greenish reflections, while the 

 Lesser Scaup Duck geiierally has the head glossed with purplish, but these 

 characters cannot lie always depended upon and the main difference is one 

 of size. 



