Knob billed Duck (Subspecies Sarkidiornis melanotos melanotos) iNaturalist Female Knob Billed Duck (Sarkidiornis melanotos) Joel Sartore 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