The American black duck is a large dabbling duck similar to the mallard. They have dark chestnut feathers on their bodies and are slightly lighter on the neck and head. In flight, a purple-blue speculum, or patch, can be seen on the wing, and the underside of the wings is much lighter than the rest of the duck's feathers. Their legs and feet are red.
One of the most discerning traits of the American black duck is the fact that, unusually for birds, the male and female are very similar. They differ only in the color of the beak and the difference is most notable during the mating season. While the male American black duck has an olive green to yellow bill, the female has a duller, more olive green one. The scientific name for the American black duck is Anas rubripes.
The American black duck is found in the US and Canada and the population at one time was steadily declining. The true cause of this is uncertain but it is thought that possibly the mallard duck population has expanded and inter-breeding has occurred while they have also taken over breeding grounds previously inhabited by the American black ducks. Conservation efforts and restricted hunting have, however, resulted in their numbers rising.
Most commonly the American black ducks live along the Northeastern coast of the US in forested wetlands or marshy areas and they may migrate seasonally. During fall and winter the breeding pairs come together. They remain together through the winter into breeding season when the female lays her eggs, usually between nine and ten of them. The male then leaves the female to incubate the eggs and goes through a molting process, leaving him flightless for a month.
The eggs of the American black duck are usually white to greenish. When the ducklings are born they are able to swim and feed themselves, and as soon as they're big enough the mother duck goes through the molting period too. By August both sexes are able to fly again.
American black ducks are omnivorous, that is they eat both vegetable and animal products. They dabble, or dip down into the water, feeding on plant materials and small animals under the surface and may occasionally dive deeper down. In freshwater these animals may include aquatic insects or amphibians, like tadpoles, and in saltwater environments they may include crustaceans and mollusks. They may occasionally scrabble for food on land, but this is unusual.