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.
the same bird preening
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.