Photos and pictures of: knob billed duck (Sarkidiornis melanotos), Sabi Sands, Greater Kruger National Park, South Africa The Africa Image Library The Knob billed Duck (Sarkidiornis melanotos) is hard to missthe males grow a huge black knob on top of their bill during the breeding season. Found across Africa and South Asia, these ducks 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 Knob billed Duck eBird