Knob billed duck (Sarkidiornis melanotos) female isolated in white backgound in Kruger National park, South Africa Stock Photo Alamy Knob billed Duck eBird Female Knob Billed Duck (Sarkidiornis melanotos) Joel Sartore Day 5: Knob billed Duck (Sarkidiornis melanotos) One of the most unmistakable ducks in southern Africa, the knob billed duck is named for the prominent black knob on the male's bill, especially noticeable Birds of India Bird World: Knob billed duck images