Knob billed Duck Holmen Birding Safaris 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 Knob billed Duck The knob billed duck (Sarkidiornis melanotos) is a duck found in tropical wetlands in Sub Saharan Africa, Madagascar and the Indian Subcontinent Stock Photo Alamy