Lophodytes cucullatus

Merganser Mer*gan"ser, n. [Sp. merg['a]nsar, fr. mergo a diver (L. mergus, fr. mergere to dip, dive) + ['a]nsar goose, L. anser.] (Zo["o]l.) Any bird of the genus {Mergus} ({Merganser}), and allied genera of the subfamily Merginae. They are allied to the ducks, but have a sharply serrated bill, eat fish, and dive for food. Also called {fish duck}. [1913 Webster +PJC]

Note: The red-breasted merganser ({Merganser serrator}) inhabits both hemispheres. It is called also {sawbill}, {harle}, and {sheldrake}. The American merganser ({Merganser Americanus}.) and the hooded merganser ({Lophodytes cucullatus}) are well-known species.

{White merganser}, the smew or white nun. [1913 Webster]