General

Common Merganser: Large, sleek diving duck with black upperparts and white underparts. Head and upper neck are green-black with head crest usually not visible. Long, thin bill is bright red. Wings are black with extensive white patches. Female is gray overall with red-brown, crested head and neck, white chin, dull white upper breast and belly, and orange bill. Juvenile resembles female but has more white on chin, a faint white eye-ring, and duller bill. Eclipse male resembles both but is more distinctly dark and light gray mottled.

Range and Habitat

Common Merganser: Breeds from eastern Alaska to Newfoundland on wooded rivers, ponds, and lakes. Spends winters in south as far as Mexico, mainly on large lakes and rivers, occasionally on saltwater.

Breeding and Nesting

Common Merganser: Six to seventeen light buff or yellow eggs are laid in a down-lined hollow on the ground or in a tree cavity. Incubation ranges from 28 to 35 days and is carried out by the female; young begin to fly at 65 to 70 days.

Foraging and Feeding

Common Merganser: Feeds on insects, small fish, and aquatic plants. Forages by diving from the surface and chasing down prey underwater; hooked upper mandible with serrations are designed to catch slippery fish.

Vocalization

Common Merganser: Call is that of low, rasping croaks.

Similar Species

Common Merganser: Red-breasted Merganser has streaked or spotted breast, gray sides, and distinct crest.