Mexican Duck

Adult drake (top) and hen (bottom) Mexican Ducks taken in Arizona. Note the drake’s dark chest and bright yellow bill. Note, too, the double white wing bars.

Mexican Ducks (Anas diazia), aka Mexican Mallards, can be difficult for identification because this species, like Mottled Ducks, look very similar to Mallard hens with darker plumage. This is because they are a part of the North American “Mallard Complex” consisting of American Black Duck, Mallard, Mexican Duck, and Mottled Duck, which are all related.  Previously considered a mallard subspecies, in 2020, the American Ornithological Society officially deemed Mexican Ducks a distinct North American species. as one of the least studied and well-known waterfowl in America, Mexican Duck drakes of this species display a pale head and rich ruddy-colored chest that differ from the rest of their brown plumage.

The only difference in plumage between Mexican mallard sexes is that the hen’s chests are the same color as the rest of their body. Since both sexes have the same dusky orange colored legs and general plumage, the easiest way to distinguish between sexes using the bill color and relative body size. Experienced hunters have little problem shooting drakes only for these reasons. The hen’s bill more closely matches the orange leg color than the drake’s pale-yellow bill. Both have an iridescent blue-green speculum and light linings that contrast with the darker underwings readily seen during flight. As compared to other species within this mallard complex, only the Mexican Duck and Mallard express double white wing bars bordering their speculum.