Photo: Jessica_Botzan/Great Backyard Bird Count Participant

Red-breasted Merganser

Mergus serrator

A slim, crested, fish-eating duck, commonly seen around jetties and piers along the coast. Superficially this species is quite similar to the Common Merganser. However, the Red-breasted Merganser nests farther north, winters mostly on salt water, and nests mainly on the ground, while the Common winters mostly on fresh water and nests in cavities.
Conservation status Numbers are thought to be stable, but the species could be vulnerable because it forms such dense concentrations at certain times and places during migration, such as late fall on Lake Erie.
Family Ducks and Geese
Habitat Lakes, open water; in winter, coastal bays. During nesting season around lakes and rivers, within the northern forest and northward into tundra regions. In winter mostly on coastal waters, including bays, estuaries, and open ocean; a few winter on ice-free reservoirs and large rivers.
A slim, crested, fish-eating duck, commonly seen around jetties and piers along the coast. Superficially this species is quite similar to the Common Merganser. However, the Red-breasted Merganser nests farther north, winters mostly on salt water, and nests mainly on the ground, while the Common winters mostly on fresh water and nests in cavities.
Photo Gallery
  • adult male, breeding
  • adult female
  • adult male, breeding
  • adult male, breeding
Feeding Behavior

Forages by diving and swimming underwater. Sometimes a group appears to hunt cooperatively, several birds lining up and driving schools of small fish into very shallow water, where the mergansers scoop them up without diving.


Eggs

usually 7-10, sometimes 5-13. Olive-buff. Females sometimes lay eggs in each others' nests, occasionally in nests of other ducks. Incubation is by female only, 29-35 days. Young: Within a day after eggs hatch, female leads young to water, where they feed themselves. 2 or more broods may join, tended by 1 or more adult females, but young are left on their own within a few weeks. Young are capable of flight about 2 months after hatching.


Young

Within a day after eggs hatch, female leads young to water, where they feed themselves. 2 or more broods may join, tended by 1 or more adult females, but young are left on their own within a few weeks. Young are capable of flight about 2 months after hatching.

Diet

Mostly fish. Feeds mainly on small fish, also crustaceans, aquatic insects, and sometimes frogs, tadpoles, or worms. Young ducklings eat mostly insects.


Nesting

In courtship display, male stretches neck forward and upward, then suddenly dips neck and forepart of body underwater, with head angled up out of water and bill open wide. Nest: female selects site on ground, usually near water, in a spot sheltered by dense plant growth or debris. Sometimes nests inside hollow stump, under rock, or in shallow burrow. Nest is a simple depression, lined with down.

Illustration © David Allen Sibley.
Learn more about these drawings.

Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

May migrate later in spring and earlier in fall than the Common Merganser. Migrating flocks fly in V-formation or lines.

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Migration

May migrate later in spring and earlier in fall than the Common Merganser. Migrating flocks fly in V-formation or lines.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon
Songs and Calls
Usually silent; various croaking and grunting notes during courtship.
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

Red-breasted 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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