The Comb Duck, Sarkidiornis melanotos, is an unusual duck, best placed in the shelduck subfamily Tadorninae, though it has formerly been included in the Anatinae.

It breeds in the tropics in South America, sub-Saharan Africa and India. It is largely resident, apart from dispersion in the wet season. It nests mainly in tree holes, laying 7-15 eggs.

The habitat is still freshwater swamps and lakes, where this duck feeds on vegetation by grazing or dabbling.

An African comb duck

This common species is unmistakable. It has a white neck, head and underparts, and glossy blue- black upperparts. The head is freckled with dark spots. The male is larger than the female, and has a large black knob on the bill. Young birds are brown above and buff below.

South American birds, S. m. sylvicola, are smaller and have black flanks (white in Old World Birds).

Reference

• Wildfowl by Madge and Burn, ISBN 0-7470-2201-1