Scientific Name: Anas americana
Population Estimate: 2.2M, Least Concern status
Range: There is a year-round population in parts of the American West. From here the breeding range extends into Canada and Alaska, with the winter range extending south to the northern tip of South American and along both US coasts. Preferred habitat is shallow fresh water, surrounded by grassland.
Field Notes: Dabbling duck. Male in breeding plumage (bottom photo) notable for wide green eye marking, buff stripe down the forehead, light bill with dark tip, white wing patches, and black rump bordered by white. Female and nonbreeding male (top photo) with grey and finely marked head, grey bill with dark tip, rufous flanks with a variable amount of white. The Eurasian Wigeon, which periodically turns up in the US and Canada, lacks the green eye marking of the breeding male and have rufous heads, not grey in both sexes.
Personal Notes: I always seem to recognize wigeons by the eye smudge first.