These plump little divers are the smallest ducks in North America. The males are easy to identify, with their round, puffy heads and steep foreheads. They’re mostly iridescent black-green with a large snow-white patch at the back of the neck.
The females are dull gray-brown and have small, oval white cheek patches. They winter in small flocks and dive for small fishes, crabs and barnacles. You may hear them before you see them. When they take off, they skitter along the surface on swift wing-beats.