The Knob billed Ducks in Songkhla Zongzhuang Birding 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 Photos Knob billed Duck Sarkidiornis melanotos Birds of the World Duck Knob billed (Sarkidiornis melanotos) female Kruger South Africa World Bird Photos Knob billed Duck, Sarkidiornis melanotos. A Knob billed Duck shows off its iridescent feathers as it flies past. This species is found along the tropical sub tropical wetlands and waterways of Sub Saharan Africa and the island