Duck hunter Mike Wec thought he had possibly shot a game-farm mallard hybrid in Massachusetts last season. Now, genetic testing has revealed it was a 100 percent leucistic American Black Duck.

The black duck is often mistaken for a hen mallard on the wing. But a closer side-by-side comparison will quickly reveal the black duck’s much darker chocolate-brown feathers.

“In the duck world, it’s the male who does the courting, it does the choosing. So this wood duck — he’s making the unusual choice every year to want to be with a mallard female.