The knob billed duck (Sarkidiornis melanotos) aka African comb duck, is found in tropical wetlands in Sub Saharan Africa, Madagascar and the Indian Subcontinent from northern India to Laos and extreme southern China. 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 eBird This is the KNOB BILLED DUCK, also known as the African Comb Duck (Sarkidiornis melanotos) This striking waterfowl is instantly recognizable by the large black knob on the bill of adult