The American black duck (Anas rubripes) is the darkest of the dabbling ducks. At first glance, it is easily dismissed as a particularly dark female of just about any duck species. But if you manage to get a good look, notice its intricately patterned feathers, dark brown-black with paler edges. Also note the relatively light-colored head and neck, as well as the metallic blue to purple wing patch bordered in black. The American black duck’s feet vary in color from red to orange to brown.
Male and female ducks look very much alike in this species. The only way to tell them apart is by looking at the bill. The male’s bill is bright yellow, while his mate’s bill tends to be duller, almost an olive color.
In flight, note the silvery underwings, contrasting sharply with the dark body. When seeing the topside, note that the metallic violet wing patch unfolds to become a brilliant speculum bordered in black. The American black duck flies swiftly and powerfully.
Best Field Marks
- Dark body with contrasting light head.
- Violet speculum bordered with black.
- Silvery underwings best seen in flight.
The male American black duck croaks, while the female quacks like a mallard.
Distribution & Occurrence
Unfortunately, the American black duck has become a rare sight in Kansas, due largely to competition and hybridization with the mallard. It migrates through Kansas, first appearing in late October at bodies of water across the state, spending the winter where open water is available, and departing in late March. It is rare in the eastern half of the state and at Cheyenne Bottoms, but appears only casually elsewhere. It has been known to summer and occasionally breed at Cheyenne Bottoms.
The American black duck is extremely wary, and it is endowed with particularly sharp hearing. On the slightest hint of danger, it immediately launches itself into the air, not requiring a running start to get off the ground.
This duck often prefers to feed at night, primarily dabbling in shallow water. Its diet consist mainly of plants in the winter, but it eats more aquatic insects in the summer to meet the extra energy demands of the breeding season.
American black ducks pair off in the fall and winter. After they migrate to the breeding grounds, the male establishes his territory while the female builds the nest. This is often a shallow depression in a well-hidden location, sometimes on the ground, sometimes on top of a stump or in a tree cavity. The nest is made of plants and lined with down. It may contain 6 to 12 cream-colored to greenish-buff eggs. The female incubates them for 23 to 33 days. The male stands guard at first, but eventually leaves the nesting site. The ducklings are able to walk and swim immediately after hatching, so the female takes them to water and helps them find food. The young grow their feathers after about two months. They migrate to winter quarters with their mother, and sometimes the male duck will join them to reestablish a pair bond with the female.
The American black duck is hard to attract, thanks to its wary nature. It will come to decoys, but only with patience and considerable coaxing.
Female, hybrid, and nonbreeding male mallards can all be potentially confused with American black ducks. First off, note that the male mallard retains his cinnamon breast while molting (eclipse plumage), even though it might look somewhat washed out. Also note that he is lighter than most black ducks and that his blue wing patch is bordered with white, not black. As for the female mallard, compare her light pattern and mottled bill to the dark body and yellow or olive bill of the American black duck. The female mallard also shows a white-bordered speculum. The mallard regularly hybridizes with the American black duck, and the resulting offspring show characteristics of both species that can make them hard to identify. The only way to pin down the identification of a hybrid bird is to take stock of the field marks and see if the duck in question displays some traits of each species.
American Black Duck
Photos, audio, and more information from Cornell’s All About Birds site.