DUCKS, GEESE, AND SWANS: Family Anatidae [159] 



species of scaups in the field except under particularly favorable condi- 

 tions makes it hard to determine their relative abundance. Aside from 

 the larger size and heavier bill, the chief distinction, found only in adult 

 males, is in the color of the iridescent reflection on the head. In marila 

 this is green, while in affinis it is purple. Both writers have consistently 

 examined hunters' bags whenever it was possible to do so. Despite what 

 Bendire and Merrill have said, we have never had an actual specimen in 

 hand in eastern Oregon and, as will be noted by checking the above 

 records, have found this duck regularly only on the coast and as a 

 straggler inland. It possibly occurs in small numbers more or less regu- 

 larly on the Columbia and should be found at least casually on the Snake 

 River, Upper Klamath Lake, and similar situations in eastern Oregon. 

 To date, however, we have failed to detect it. 



No Oregon stomachs of this duck have been examined, but there is no 

 reason to believe that the food differs materially from that of the Lesser 

 Scaup. 



Lesser Scaup Duck: 



Nyroca affinis (Eyton) 



DESCRIPTION. "Like Nyroca 1 marila, but smaller, with black of head glossed with 

 purple instead of green, and sides more heavily lined with gray." (Bailey) Downy 

 young: "The downy young is darkly and richly colored. The upper parts are dark, 

 lustrous 'mummy brown' or 'sepia,' shaded with 'brownish olive'; these colors are 

 darkest and most lustrous on the posterior half of the back and lightest on the 

 shoulders; the dark colors cover the upper half of the head and neck, the back and 

 the flanks, fading off gradually into a dusky bank around the lower neck and en- 

 croaching on the ventral region posteriorly. The color of the under parts, which 

 covers the lower half of the head, throat, breast, and belly, varies in different indi- 

 viduals; in some it runs from 'olive ocher' to 'primrose yellow'; but in most speci- 

 mens from 'chamois' to 'cream buff'; these colors are brightest and richest on the 

 cheeks and on the breast. The markings on the head are usually indistinct, but a 

 superciliary buff stripe, a loral dusky stripe and a postocular dusky stripe are dis- 

 cernible in the majority of a series of n specimens in my collection. There is also an 

 indistinct yellowish spot on each scapular region, but none on the rump." (Bent) 

 Si%e- "Length 15.00-16.50, wing 7.50-8.2.5, bill 1.58-1.90, width of bill .80-. 95." 

 (Bailey) Nest: A hollow in the ground, lined with a little dry grass and down, 

 usually in a tuft of grass or beneath a bush near the water. Eggs: 6 to 15, usually 9 

 to ix, dark olive buff in color. 



DISTRIBUTION. General: Breeds from northern limit of timber west of Hudson Bay 

 south to northern Ohio, southern Wisconsin, southeastern Iowa, northwestern 

 Colorado, and central British Columbia. Winters from southern United States south 

 to Central America. In Oregon: Abundant winter resident from September to about 

 May i. Stragglers remain throughout summer but are nonbreeding birds so far as 

 we know. 



OUR OWN EXPERIENCE, as well as a check of many hunters' kills, demon- 

 strates that in Oregon the Lesser Scaup Duck is much the more abundant 



1 Nyroca=-Aythya. 



