This fine looking duck is an American wigeon. The males, or drakes, have a large green patch on the side of the face. The females, or hens, are much less conspicuous and more uniformly brown in color. These guys are also sometimes called baldpates because of the whitish strip across the top of the head. This photo was taken on my recent owl outing at Reifel Bird Sanctuary in British Columbia, Canada.
Nikon D800 with Nikkor 200-400mm lens (at 400mm) ISO 800, f/4 at 1/1000th of a second