The origins of the Cayuga are obscure. A much-repeated theory that it descends not from the Mallard like almost all domestic ducks, but from "Anas rubripes", the American Black Duck, remains unsubstantiated and unverified by any scientific evidence. Unlike "Anas rubripes", the Cayuga is a true black in color; this color is the result of a genetic mutation fairly common in breeds derived from "Anas platyrhynchos". The Cayuga has other characteristics compatible with derivation from the Mallard; in particular, it shows the typical curled "drake feather" in the tail, while "Anas rubripes" does not.