The male American Black Duck, Anas rubripes, has a dark body and light head, orange-red legs, unblemished yellowish bill, and a black-bordered blue speculum — the brightly colored patch of feathers on the wing.
The black duck in the photos is locally famous among birdwatchers in Brooklyn, New York, for pairing with a female Mallard, Anas platyrhynchos. She is easily distinguished by a white-bordered blue speculum, black-splotched orange bill, and other mallard field marks. They were loafing together in a small pond in Brooklyn Bridge Park. The male had just chased away a male Mallard! A similar couple, perhaps the same one, was seen with chicks on the East River, not far from this spot, last year.
Stretching, below, shows off the male’s violet-blue speculum and brightly colored foot. The color of the speculum seems to change with the light. This is the same bird as above.
Visit my blog for more about this couple and other urban wildlife. For even more, see my book, Field Guide to Urban Wildlife.