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Guide to North American Birds

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Adult female and downy young. Photo: Lynn Cleveland/Audubon Photography Awards

Common Merganser

Mergus merganser

This fish-eating duck is the typical merganser of freshwater lakes. Its flocks are usually small, but these may combine into big concentrations sometimes at large reservoirs. Common Mergansers living along rivers may spend hours resting on rocks or on shore. The British call this bird the "Goosander." In some parts of Europe, with artificial nesting sites provided, the species has become a common nesting bird along city waterfronts; this has not yet happened in North America.

Conservation status	May be increasing in Europe; apparently stable in North America.
Family	Ducks and Geese
Habitat	Wooded lakes, rivers; in winter, rarely coastal bays. Mainly around fresh water at all seasons. Summer: on shallow but clear rivers and lakes in forested country; avoids dense marshes and muddy waters. Winter: on lakes, large rivers; occasionally on bays along coast.

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Feeding Behavior

forages by diving and swimming underwater, propelled by its feet, stroking with both feet in unison. Finds most food by sight; may swim along surface, dipping head underwater repeatedly until prey is spotted, then diving in pursuit.

Eggs

8-11, sometimes 6-13. Pale buff. Females often lay eggs in each others' nests. Incubation is by female only, 30-35 days. Young: May remain in nest a day or more after hatching; then they climb to cavity entrance and jump to ground. Female tends young birds for several weeks, but young feed themselves; they may survive even if abandoned quite early. Young are capable of flight about 65-70 days after hatching.

Young

May remain in nest a day or more after hatching; then they climb to cavity entrance and jump to ground. Female tends young birds for several weeks, but young feed themselves; they may survive even if abandoned quite early. Young are capable of flight about 65-70 days after hatching.

Diet

mostly fish. Eats a wide variety of fish; also will eat mussels, shrimp, salamanders, rarely plant material. Adult males may swallow fish more than 1 foot long. Young ducklings eat mostly aquatic insects.

Nesting

Courtship displays of male include swimming very rapidly in circles near female; suddenly stretching neck upward, pointing bill straight up, and giving soft call. Nest site is near water, usually in large tree cavity; also in crevices in rock, in holes under tree roots or undercut banks, or in nest boxes. Occasionally in buildings. Nest of wood chips or debris in cavity, plus lining of down.

Illustration © David Allen Sibley.
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Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

Migrates mostly in small groups. Adult males, on average, seem to winter farther north than females and young. Migration is late in fall and early in spring.

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Migration

Migrates mostly in small groups. Adult males, on average, seem to winter farther north than females and young. Migration is late in fall and early in spring.

All Seasons - Common
All Seasons - Uncommon
Breeding - Common
Breeding - Uncommon
Winter - Common
Winter - Uncommon
Migration - Common
Migration - Uncommon

Songs and Calls

Low rasping croaks.

Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
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How Climate Change Will Reshape the Range of the Common Merganser

Audubon’s scientists have used 140 million bird observations and sophisticated climate models to project how climate change will affect this bird’s range in the future.

Zoom in to see how this species’s current range will shift, expand, and contract under increased global temperatures.

Climate Threats Near You

Climate threats facing the Common Merganser

Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.