Hartlaub's duck

Hartlaub's duck (Pteronetta hartlaubii) is a dark chestnut-coloured duck of African forests. Formerly included in the paraphyletic "perching duck" assemblage, it was later moved to the dabbling duck assemblage. However, it is fairly distinct from the "typical" dabbling ducks, and is placed in the monotypic genus Pteronetta. It is named after the German naturalist Gustav Hartlaub.

Analysis of mtDNA sequences of the cytochrome b and NADH dehydrogenase subunit 2 genes suggests that it belongs into a very distinct clade—possibly a subfamily of its own—together with the blue-winged goose, another African species of waterfowl with uncertain affinities.

On average, Hartlaub's ducks range from 56–58 centimeters (22–23 in) in height. This species of duck is monotypic, meaning there is only one type of this species. Juveniles have feathers with pale tips on their breast and abdomen. Their adult coat is fully grown after six months. Adult males weigh between 925 and 1,140 grams (32.6 and 40.2 oz), and they have a white head with reddish-brown eyes. The females have barely any white on their heads, have dark red eyes, and weigh between 770 and 805 grams (27.2 and 28.4 oz). The amount of white on each duck's head will vary. Both sexes have a blue patch on their wing that distinguishes them from other waterfowl. During mating season, the base of the male's bill will enlarge.