Pato crestudo (Sarkidiornis melanotos) Comb Duck (Sarkidiornis sylvicola) Birds of Bolivia 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 Female Knob Billed Duck (Sarkidiornis melanotos) Joel Sartore Sarkidiornis melanotos Monaco Nature Encyclopedia