They measure 19–26 inches (48–66 cm). Male has green head with wispy crest, gray sides, white neck ring, and rusty breast. Female greyish, with reddish-brown head shading gradually into gray of neck. Both sexes are crested and have red bills.
Breeds on wooded lakes and tundra ponds; winters mainly on salt water.
Eight to 10 olive-buff eggs in a down-lined depression concealed under a bush or in a brush pile.
Breeds in Alaska and across northern Canada to Newfoundland and south to Great Lakes. Winters chiefly along coasts from Alaska south to California, from Maritime Provinces south to Florida, and along Gulf Coast. Also in Eurasia.
Usually silent; various croaking and grunting notes during courtship.
The red-breasted merganser breeds farther north than its relatives and is also the most common winter merganser on salt water, especially where rocky coves provide good fishing. Like the other two species, it lives mainly on fish, which it captures in swift underwater dives, aided by its long pointed bill lined with sharp, tooth-like projections. Often found searching for food alone, these birds also gather in large flocks where fish are abundant.