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.
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.
Photo Gallery
  • adult male, breeding
  • adult female, breeding
  • adult male, breeding
  • adult female
  • adults, nonbreeding
  • breeding adult female with ducklings
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.
Learn more about these drawings.

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 could affect this bird's range

In the broadest and most detailed study of its kind, Audubon scientists have used hundreds of thousands of citizen-science observations and sophisticated climate models to predict how birds in the U.S. and Canada will react to climate change.

Learn more

Read more: climate.audubon.org
Duck-like Birds Mergansers

Common Merganser

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season.

More on reading these maps.

Each map is a visual guide to where a particular bird species may find the climate conditions it needs to survive in the future. We call this the bird’s “climatic range.”

The colors indicate the season in which the bird may find suitable conditions— blue for winter, yellow for summer (breeding), and green for where they overlap (indicating their presence year-round).

The darker the shaded area, the more likely it is the bird species will find suitable climate conditions to survive there.

The outline of the approximate current range for each season remains fixed in each frame, allowing you to compare how the range will expand, contract, or shift in the future.

The first frame of the animation shows where the bird can find a suitable climate today (based on data from 2000). The next three frames predict where this bird’s suitable climate may shift in the future—one frame each for 2020, 2050, and 2080.

You can play or pause the animation with the orange button in the lower left, or select an individual frame to study by clicking on its year.

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season. More on reading these maps.
Winter
Summer

Winter Range
Summer Range
Both Seasons
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