Stiff-tail Ducks

The Ruddy Duck (Oxyura jamaicensis) is a North and Central American duck. The male has a rich chestnut plumage with a black cap, big white cheek patch and blue bill. The female is duller and has a dark bill.

Female Ruddy Duck in NY, US ©Tan KH

The Masked Duck (Nomonyx dominicus) is found in Central America.

The Black-headed Duck (Heteronetta atricapilla), Andean Duck (O. ferruginea) and Lake Duck (O. vittata) are South American ducks.

The Maccoa Duck (O. maccoa) is an African duck, while the White-headed Duck (O. leucocephala) is an Old World duck.

Blue-billed Duck (O. australis) is endemic to Australia. The breeding male has a rich chestnut plumage with a blackish head and blue bill. The female is dark grey with fine pale bar all over.

The Musk Duck (Biziura lobata) is endemic to Australia. It has a dark plumage and a lobe under the bill, which is much reduced in the female.

Musk Duck in Melbourne, Australia ©Tan KH

Reference
http://www.worldbirdnames.org/ioc-lists/master-list-2/