Male Mallards’ green heads and duck tails (the original by the way) are distinctive. And familiar. On maybe the most recognizable duck in North America. Or even the world.
Plus there are 13 closely related species running around the continent. Several of those closely resemble the Mallard. The Mottled Duck, the Black Duck and one subspecies: the Mexican Duck (or Southern Mallard.) They all can be difficult to ID. Males and females of these species look like the female Mallard. Plain, that is. And to mix it up further so does the male Mallard in the off season. [See Bird-Call “Eclipse Plumage”]
And they sound more-or-less the same too: “Quack, Quack!” in 13 local dialects. One may be a little softer. One may be a little raspier. Well you get the picture.
But the Mexican Duck is probably the most difficult to distinguish. Of all of them it looks most like the Mallard female. Besides that, north of Mexico they interbreed to the point it’s hard to find a pure Mexican Duck. And even the difference in quacks is subtle.
So how do you tell? Listen carefully. They sound similar, but there is a difference.
Female Mallards give their famous, “Quack! Quack!” Brash and loud.
Mexican Ducks, on the other hand, say politely …
“Guac! Guac!”
:)
