Black-headed Duck

About the Black-headed Duck

The black-headed duck (Heteronetta atricapilla) is a South American duck in subfamily Oxyurinae of family Anatidae. It is found in Argentina, Bolivia, Brazil, Chile, Paraguay, and Uruguay. The black-headed duck is the only member of genus Heteronetta and has no subspecies. It is closely related to the "stiff-tailed" ducks of genera Nomonyx, Oxyura, and Biziura.

The black-headed duck is the most basal living member of its subfamily, and it lacks the stiff tail and swollen bill of its relatives. Overall much resembling a fairly typical diving duck, its plumage and other peculiarities indicate it may not be a very close relative of the other stiff-tailed ducks, but rather the product of convergent evolution from the ancestors of the stiff-tailed ducks.

The black-headed duck is about 35 cm (14 in) long. Males weigh an average of about 510 g (18 oz) and females 565 g (20 oz). The species has a distinctive shape, with a long body and disproportionately short wings. Its bill has a black maxilla and an orange mandible; the maxilla has a rosy patch at its base during the breeding season. Adult males have a glossy black head and upper neck and... Wikipedia →