Common Merganser Bird Facts (Mergus merganser)

Visual Identification

Appearance

The Common Merganser is a large, streamlined duck with a distinctive long, narrow bill. Males have a dark green head, white body, and black back, while females display a grey body with a rusty cinnamon head and white chin.

Both sexes have a bright red, serrated bill and orange legs. Juveniles resemble females but with a shorter crest and duller overall colouration.

Size

Length

58cm to 68cm

Wingspan

78cm to 94cm

Weight

1000g to 2.1kg

Colours

Male Female

Primary Colour

White Black Green

Secondary Colour

Red Grey

Beak Colour

Red

Leg Colour

Orange

Primary Colour (Female)

Grey Brown

Secondary Colour (Female)

White

Beak Colour (Female)

Red

Leg Colour (Female)

Orange

Habitat and Distribution

Habitats

Woodland

The Common Merganser is not typically found in Woodland habitats.

Garden

The Common Merganser is not typically found in Garden habitats.

Wetland

The Common Merganser can be found in Wetland habitats.

Coastal

The Common Merganser can be found in Coastal habitats.

Urban

The Common Merganser is not typically found in Urban habitats.

Farmland

The Common Merganser is not typically found in Farmland habitats.

Grassland

The Common Merganser is not typically found in Grassland habitats.

Desert

The Common Merganser is not typically found in Desert habitats.

Tundra

The Common Merganser is not typically found in Tundra habitats.

Rainforest

The Common Merganser is not typically found in Rainforest habitats.

Mountain

The Common Merganser is not typically found in Mountain habitats.

Savanna

The Common Merganser is not typically found in Savanna habitats.

Distribution

Common Mergansers inhabit clear, fish-rich freshwater bodies, including lakes, rivers, and reservoirs. They are found across northern North America, Europe, and Asia, with populations extending into more temperate regions.

Some birds move to coastal areas or larger unfrozen water bodies in winter. They are widespread in Canada, the northern United States, and parts of Europe, including the UK, where they are known as Goosanders.

Elevation Range

Sea level to 2,000 meters

Climate zones

Temperate, Subarctic

Distribution Map

This map gives you a rough idea of where you might spot a Common Merganser. The coloured areas show countries where these birds have been seen.

A few things to keep in mind:

Birds might not be everywhere in the coloured areas, for example, they may be present around the coast of that country
Where birds live can change with seasons and available food
This map is quite simple - it doesn't show exact locations

We're working on making our maps even better! Soon, we hope to show you:

More detailed maps for bigger countries, including state and region
How birds move around during different seasons

Resident

Breeding

Non-breeding

Vagrant

Distribution by Region

Species that can be found in the area throughout the year

Albania Austria Bangladesh Belarus Bermuda Bhutan Canada China Croatia Czech Republic Denmark Estonia Finland France Germany Greece Iceland India Ireland Italy Japan Kyrgyzstan Latvia Lebanon Lithuania Macedonia Mexico Moldova Montenegro Myanmar Nepal North Korea Norway Pakistan Poland Romania Russia Saint Pierre and Miquelon Serbia Slovenia South Korea Sweden Switzerland Taiwan The United Kingdom Turkmenistan Ukraine

Species that are present in the area during their breeding season

Afghanistan Kazakhstan Mongolia Russia Tajikistan United States of America Uzbekistan

Species that are present in the area outside their breeding season

Azerbaijan Belgium Bulgaria Hungary Iran Iraq Liechtenstein Luxembourg Netherlands Slovakia Spain Turkey

Species that appear infrequently (rare) and unpredictably outside their normal range

Algeria Cyprus Greenland Israel Malta Morocco Portugal Svalbard and Jan Mayen Islands Tunisia

Behaviour and Ecology

Bird Attributes

This feature is in beta. We'd love your feedback to improve it!

Share your thoughts

Bird Attributes Explained

Our bird attributes system rates various aspects of a bird's capabilities on a scale of 0-100, based on data from field observations, scientific studies, and expert knowledge.

Attribute Categories:

Agility: Manoeuvrability, speed, and grace in flight or movement.
Strength: Physical power, often correlating with size and hunting abilities.
Adaptability: Ability to thrive in various environments or changing conditions.
Aggressiveness: Territorial behaviour and assertiveness, particularly during breeding seasons.
Endurance: Stamina, often seen in migration patterns or foraging behaviours.

Understanding the Ratings:

0-20: Very Low
21-40: Low
41-60: Average
61-80: High
81-100: Very High

Remember, these attributes are relative to other bird species and don't necessarily indicate superiority.

Hover over the icon next to each attribute for more information.

Tap the icon next to each attribute for more information.

Agility 85

Agility

Reflects the bird's manoeuvrability, speed, and grace in flight or movement.

The Common Merganser displays remarkable agility, particularly in aquatic environments. As excellent divers, they can manoeuvre swiftly underwater, staying submerged for up to 2 minutes whilst pursuing fish. Their streamlined body and powerful legs contribute to their impressive underwater agility.

Strength 70

Strength

Indicates the bird's physical power, often correlating with size and hunting abilities.

These large diving ducks possess considerable strength, evident in their ability to dive to depths of 9 metres and catch fish up to 30 cm in length. Their powerful legs propel them efficiently through water, and they can take off from water surfaces despite their size, indicating good muscular strength.

Adaptability 80

Adaptability

Represents the bird's ability to thrive in various environments or changing conditions.

Common Mergansers demonstrate high adaptability, thriving in various freshwater habitats from sea level to 2,000 metres elevation. Their ability to switch between freshwater and coastal environments, coupled with their partial migratory behaviour, showcases their adaptable nature. They've also adapted well to using artificial nest boxes when natural cavities are scarce.

Aggressiveness 60

Aggressiveness

Measures the bird's territorial behaviour and assertiveness, particularly during breeding seasons.

While not overtly aggressive, Common Mergansers display territorial behaviour during breeding season, with males performing elaborate courtship displays. They may engage in disputes over nesting sites or feeding areas. Their predatory nature in fishing also suggests a moderate level of assertiveness.

Endurance 75

Endurance

Reflects the bird's stamina, often seen in migration patterns or foraging behaviours.

The endurance of Common Mergansers is evident in their long-distance migrations, diving capabilities, and ability to withstand cold temperatures in northern habitats. Their capacity to dive repeatedly for food and their widespread distribution across different climate zones indicate good stamina and resilience.

Diet

Common Mergansers primarily feed on fish, using their serrated bills to grip slippery prey. They also consume aquatic invertebrates, amphibians, and occasionally small mammals or birds. These efficient predators can consume fish up to 30 cm in length.

In the past, they have been targeted by commercial fish farms following their penchant for trout and salmon, although more commonly, they will feed on the more abundant species of fish available within their immediate habitat.

Behaviour

Common Mergansers are excellent divers, using their powerful legs to propel themselves underwater in pursuit of fish. They often form small flocks during winter and engage in cooperative fishing behaviour.

These birds are generally quiet but become more vocal during courtship displays.

Vocalisation

Common Mergansers are generally quiet outside the breeding season. During courtship and nesting, males produce soft, grunting calls, while females make a harsh, croaking sound.

Alarm calls consist of a low, grating 'karr-karr' that can be heard during territorial disputes.

Nesting & Breeding

Breeding begins in late winter or early spring, with pairs forming on wintering grounds. Males perform elaborate courtship displays, including head-pumping and wing-flapping.

Females typically nest in tree cavities near water, sometimes using artificial nest boxes. They lay 6-13 cream-coloured eggs in a down-lined nest.

Incubation lasts about 32 days and is performed solely by the female. Ducklings leave the nest within 24 hours of hatching, often jumping from considerable heights to reach water.

Conservation and Status

Global Conservation Status

Least Concern ^[1]

While the Common Merganser is currently listed as Least Concern, it faces threats from habitat loss and degradation of freshwater ecosystems.

Conservation efforts focus on protecting water quality and maintaining healthy fish populations in their breeding and wintering areas.

Population Data

Global Population Estimate

1,700,000 - 2,400,000 mature individuals ^[2]

Global Population Trend

Trend data may be uncertain or fluctuating

Additional Information

Quick Facts

Other names:

Goosander

Family:

Anatidae

Average Lifespan

8 years

Max Lifespan

14.8 years ^[3]

Predators

Adult Common Mergansers face threats from large raptors like Bald Eagles and Great Horned Owls, while eggs and ducklings are vulnerable to raccoons, minks, and large fish.

Did You Know?

Common Mergansers have over 100 sharp, backward-pointing projections on their bill to help grip fish.
They can dive to depths of up to 30 feet (9 meters) in search of prey.
Female mergansers sometimes lay eggs in each other's nests, a behaviour known as 'egg dumping'.