Merganser

Merganser, fish-eating duck of the family Anatidae, found in many parts of the world. It is also called the sawbill because of its long serrated bill. Both sexes have a large head crest—the male dark, and the female brown. Mergansers nest in tree holes. They include the American, red-breasted, and hooded mergansers, all of which can be found in North America.