Mallard, Of Sorts, and a Quiz

Male Mallards come in all flavors, their diversity greatest in urban parks, where they interbreed not just with the local “hen-plumaged” mallards but with all sorts of lavishly cultivated domestic breeds. This handsome drake’s brown-smudged sides and imperfectly colored head may be the reflex of a Mexican Duck somewhere high in the branches of the family tree, or he may just be running low this cycle on whatever hormones his more studly, greener-headed companions enjoy in such abundance.

And a question: can the duck whose stern intrudes at the right edge of the image be identified definitively to species?