Habitat
Grassy ponds or lakes in savanna, open woodlands along large rivers and lakes, swamps, marshes, floodplains, river deltas, flooded forest, pastures, rice-paddies. Occasionally sandbars and mudflats.
Food
Vegetable matter, including seeds of grasses and sedges, the soft parts of aquatic plants, agricultural grains, aquatic insect larvae and locusts.
Knob-billed Duck (Sarkidiornis melanotos) [XC791480]
by Dries Van de Loock from Kamfinsa Area, Copperbelt Province, Zambia (flight call)
Knob-billed Duck (Sarkidiornis melanotos) [XC791479]
by Dries Van de Loock from Kamfinsa Area, Copperbelt Province, Zambia (call)
Nest
A rough structures composed of twigs and coarse grass, in large hollow tree cavities, between 7 and 12 m above the ground, or in holes in the walls of isolated buildings. It may also use abandoned nests of other bird species, such as Hamerkop (Scopus umbretta), or nest on the ground in the shelter of tall grass or on tree stumps. When tree nesting, the same cavity may be used from year to year. In singles, pairs or small groups.
Subspecies
Subspecies sylvicola is sometimes considered full species.
The following 2 subspecies are recognised:
melanotos (Pennant, 1769) - Africa south of Sahara and Madagascar, tropical Asia from Pakistan through Indian Subcontinent to extreme southern China.
sylvicola Ihering and Ihering, 1907 - Tropical South America from Colombia to northern Argentina. Considered by some authors to be a distinct species, American Comb Duck (Sarkidiornis sylvicola).
BirdLife International Species Factsheet