Here are some random shots of some of the many waterfowl species that winter in the Willamette Valley
This Common Merganser was swimming with her face submerged, looking for fish. I have also seen loons hunt in this way.
Here she finally shows her face. The clearly demarcated white chin helps to differentiate this species from the similar Red-breasted Merganser.
This female Eurasian Wigeon is recognized by her brown head. Notice the female American Wigeon on the right with her gray head.
Here is a distant shot of a mixed flock of waterfowl (click to enlarge). From left to right, you can see Ring-necked Duck, Canvasback, Cackling Goose, American Coot, and American Wigeon.