Genus Aythya, Diving Ducks
Common Pochard (Aythya ferina) Eastern Asia - Japan, Korea, China and Thailand
Tufted Duck (Aythya fuligula) North America, Eastern Asia - Japan, China
Ring-necked Duck (Aythya collaris) Western USA - California and Washington



Redhead (Aythya americana) California, Oregon, USA




Lesser Scaup (Aythya affinis) Washington State, USA








Greater Scaup (Aythya marila) Rausu Japan, Hokkaido

Ferruginous Duck (Pochard) (Aythya nyroca) China mainly Yunnan and Chiang Rai Thailand























Canvasback (Aythya valisineria) California




