Aythya affinis | lesser scaup
The migrant lesser scaup is a common winter visitor to the Hawaiʻi. This diving duck sifts through mud to feed on shellfish and underwater vegetation. It averages 15-19 inches in length and is just a little smaller than the similar looking greater scaup. Males have a dark head with a purple sheen on a white body and females are brown with a white forehead. Both have bluish bills.