American Black Ducks are large ducks with a profile nearly identical to Mallards. They have rounded heads, thick bills, and bulky bodies. Like other dabbling ducks they sit high in the water with their tails high. They measure 54 to 59 centimeters in length, with a wingspan of 88 to 95 centimeters. American Black Ducks have very dark brown bodies with pale gray-brown heads and yellow-green bills. Females tend to be slightly paler than males, with duller olive bills. In flight, the underwings are bright white. The secondaries (speculum) are iridescent purple without white borders. These are dabbling ducks that tip up instead of dive when they forage. They eat aquatic plants, invertebrates, and occasionally small fish in shallow water. They also fly into agricultural fields to feed on waste corn and grain. Look for them mixed into flocks with other “puddle ducks” such as Gadwall and Mallards. American Black Ducks nest in eastern wetlands including freshwater and saltmarshes. During migration and winter, they rest and forage in protected ponds, marshes, and bays. This species is of low conservation concern.
Pleistocene fossils of American Black Ducks, at least 11,000 years old, have been unearthed in Florida and Georgia.
As soon as their down feathers dry, newly hatched ducklings are able to leave the nest, a depression on the ground lined with plant materials. They follow their mother to rearing areas with a lot of invertebrates to eat and plenty of vegetation for cover.
Source: American Black Duck Overview and Identification Information, All About Birds, The Cornell Lab of Ornithology