A large fish-eating diving duck with a long sharp serrated bill ("sawbill"). Males have a dark glossy green head and bright red bill; females sport a rust-red crested head.

Also called: Goosander

Native status: Native to North America

§ Quick facts

SizeBody 30–70 cm (12–28 in); wingspan 55–95 cm
Weight300–1,800 g
LifespanWild 5–20 years
OrderAnseriformes
FamilyAnatidae

§ Encyclopedia

The common merganser or goosander is a large sea duck of rivers and lakes in forested areas of Europe, Asia, and North America. The common merganser eats mainly fish. It nests in holes in trees. The name "common merganser" is used in North America, while "goosander" is used in Eurasia.

Source: Wikipedia — Common merganser Licensed under CC BY-SA 4.0

§ Identification

Field marks. Long-bodied with a thin red bill. Male has a glossy green head, white body, and black back; female gray-bodied with a sharply defined rusty head and white chin.

Similar species. Red-breasted Merganser has a shaggy crest and (male) a rusty breast band; female Red-breasted has a diffuse neck contrast versus Common's clean-cut rusty head.

Voice. Mostly silent; harsh croaks and grunts during courtship.

§ Diet & behavior

Diet. Varies by species: aquatic plants, seeds, invertebrates, fish.

Behavior. A large fish-eating diving duck of clear rivers and lakes; uses its serrated 'sawbill' to grip fish. Nests in tree cavities and broods ride on the mother's back.

§ Range

Breeds across northern North America; winters on inland waters of the US

§ Habitat

Clear lakes and large rivers near coniferous forest

§ Threats

Stream pollution affecting fish prey, loss of nest cavities, mercury accumulation in fish.

§ Conservation status

According to the IUCN Red List, the common merganser is currently classified as Least Concern.

§ What helps

Maintain clean rivers. Leave large dead trees for cavity nests. Reduce mercury emissions.

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§ Further reading

§ Sources cited

  • Cornell Lab of Ornithology — All About Birds
  • National Audubon Society
  • iNaturalist
  • IUCN Red List