The common merganser (North American) or goosander (Eurasian) (Mergus merganser) is a large sea duck of rivers and lakes in forested areas of Europe, Asia, and North America. The common merganser eats mainly fish. It nests in holes in trees.

Taxonomy

The first formal description of the common merganser was by Swedish naturalist Carl Linnaeus in 1758 in the 10th edition of his Systema Naturae. He introduced the current binomial name Mergus merganser.^[2] The genus name is a Latin word used by Pliny and other Roman authors to refer to an unspecified waterbird, and merganser is derived from mergus and anser, Latin for “goose”.^[3] In 1843 John James Audubon used the name “Buff-breasted Merganser” in addition to “goosander” in his book The Birds of America.^[4]

The three subspecies differ in only minor detail:^[5][6]