Portrait of knob billed duck (Sarkidiornis melanotos), Tanzania Photographic Print Panoramic Images AllPosters.com Image Sarkidiornis melanotos (Knob billed Duck) BioLib.cz Avise's Birds of the World This bird wears its crown not of feathers, but of horn. The Knob billed Duck (Sarkidiornis melanotos), also known as the Comb Duck, is one of the most unmistakable waterfowl in the world. African Comb Duck Sarkidiornis melanotos Borrow others' nests Comb Duck, or Knob billed Duck males have a large growth, or comb, on the top of their black beak. During breeding season, the male's Sarkidiornis melanotos (Comb duck, Knob billed duck)