African Black Ducks are mostly found on shallow, fast-flowing, rocky streams and rivers, often in mountainous or wooded areas, though they do also utilise other natural and man-made water bodies nearby. They follow an omnivorous diet, feeding on aquatic plants, grain, fruits and berries, insects, fish eggs, crustaceans and tadpoles. African Black Ducks are diurnal, doing most of their foraging at dawn and dusk, and weigh around 1kg.
African Black Ducks are territorial throughout the year, each pair occupying a considerable stretch of river. They are usually seen singly or in pairs, rarely congregating in large numbers (when they do, it is usually unmated or immature birds without a territory gathering at a popular roost). The breeding season spans most of the year with a peak in autumn and winter in South Africa. The nest is a cup of plant material lined with down, usually built on the ground on islands and river banks near the water, and surrounded by dense grass, reeds or driftwood. The female is responsible for building the nest, incubating the eggs (of which there are between 4 and 11 in a clutch) and caring for the chicks. Incubation takes about 4 weeks, the ducklings fledge at between 2 and 3 months old, and then stay with their parents for another month or two.
Despite a decreasing population, caused by degradation of their preferred riverine habitats and hybridization with feral populations of the exotic Mallard, the IUCN lists the African Black Duck as being of least concern. They are widespread over much of southern, central and east Africa, and in South Africa occurs in all our provinces, though only patchily in the arid Northern Cape.