LESSER SCAUP DUCK 273 



Iris chrome yellow. Bill bluish black. Legs and feet greenish lead-color. 



Wing 190-201 mm.; bill 40; tarsus 37. 



Weight 1 pound, 8 ounces to 1 pound, 14 ounces (0.68 to 0.85 kilograms). 



Adult Female: Like the female of the Greater Scaup (Nyroca marila) but smaller and the white 

 face-mark not so great in depth. It is not safe to attempt to distinguish the female of this species ex- 

 cept by measurements. Old specimens are blackish about the head. In breeding plumage, that is, in 

 June and July, the white face-patch is usually lost, and there are somewhat fewer vermiculated feath- 

 ers among the scapulars. 



Iris brownish yellow. Bill dark gray. Legs and feet similar to those of male but duller. 



Wing 185-198 mm.; bill 36-40; tarsus 35. 



Weight 1 pound, 4 ounces to about 1 pound, 10 ounces (0.56 to 0.73 kilograms). 



Female in First (Juvenal) Plumage: Like adult female but the white face-patch not so clearly 

 defined. Vermiculated scapulars not present at first but these are not always well defined even in 

 adult plumage. Lower abdomen more brownish and streaked than in adults. Tail faded and blunt 

 at the tip. 



Male in First (Juvenal) Plumage: Like the female, but the head soon becomes darker, and the 

 white face-patch is obscured. This sex can usually be distinguished in early autumn by the greater 

 amount of vermiculation on the scapulars. (For details of plumage changes see the account of the 

 Greater Scaup.) 



Male in Eclipse: In June the head loses its iridescence and becomes dull brownish to blackish, 

 lighter around the lower neck and forming a distinct collar. Feathers with whitish margins appear 

 among the black feathers of the breast. Later on, the mantle changes from black to a duller brownish 

 color, with fine vermiculations. The flanks also become somewhat grayer and show vermiculated 

 feathers. The scapulars lose the bright white and black appearance and look nearly like the mantle. 

 Later on in the summer white face-spots appear at the base of the culmen and the chin also becomes 

 whitish. The occiput may be black, while the cheeks, throat, and neck have a ragged appearance and 

 are brownish or grayish. The black chest-patch is apparently lost late in the summer and the breast 

 then looks almost the same as in the female. The perfect eclipse phase is not usually seen before late 

 August, and it may persist until the end of September or later. 



Young ln Down (Plate 62) : Very much like the young of the Greater Scaup and probably not to be 

 distinguished except by its smaller size. As in most downy young there is considerable variation in 

 general color, as well as in face-pattern. There is usually a fairly well-marked light streak above the 

 eye but this may be nearly absent or reduced to a mere spot above and in front of the eye. There 

 may or may not be indications of a darker streak behind or through the eye and there is usually a 

 darker patch near the angle of the jaw. The upper side is very dark brown to black, with the wing-, 

 scapular-, and rump-patches very indistinct. The yellow-buff coloring on throat and breast fades out 

 at the age of two or three weeks. 



Iris pale olive. Culmen deep olive, nail dull brownish, gular sac pale brownish yellow. Tarsus and 

 toes pale greenish olive, darker at the joints; webs dark olive. 



DISTRIBUTION 



The Lesser Scaup, a close ally of the Greater Scaup and very frequently confused with it, is a strictly 

 American species, somewhat more southern and more western in its distribution than its relative, and 

 one of our most abundant ducks. With this species more than with any other a careful „ pnpra i 

 distinction must be drawn between the breeding range and the summer range, because 



