LESSER SCAUP (Aythya affinis) 



The lesser scaup is a large duck with a glossy, dull purple head, a bluish 

 bill, and a dark breast. Its finely-flecked flanks appear white at a distance. 

 The female is generally brown with a white mask. Scaups are expert 

 divers with large and powerful feet. They generally breed on the borders 

 of freshwater marshes or ponds, but are most often observed in the open 

 water of lakes and large ponds in Yellowstone and Grand Teton. The ring- 

 necked duck, which also occurs in both parks, resembles the lesser scaup, 

 but has a dark back and a white ring on the bill. The lesser scaup, or 

 "bluebill," is a common summer and occasional winter resident in both 

 Yellowstone and Grand Teton. 



Barrow's ColdeneyG Harry Engels 



HARLEQUIN DUCK (Histrionicus histrionicus) 



This handsome duck is a rare breeding resident of remote stretches of 

 the Yellowstone and Snake Rivers and their tributaries. (Harlequins are 

 often observed on the LeHardy Rapids of the Yellowstone River in spring 

 and early summer). Like its namesake, the masked character of comedy 

 and pantomime, the male harlequin is richly colored with a gaudy pat- 

 terned plumage of blues, russets, blacks, and whites. The female is dusky- 

 colored with three round spots on either side of the head. Harlequins 

 are especially attracted to rough water. They will repeatedly fly to the 

 beginning of a series of rapids and float to their terminus, or they will 

 use both their wings and feet to move upstream against the swift-moving 

 current. Harlequins feed on water insects and their larvae, small fishes 

 and tadpoles, and acquatic plants. 



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