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Common Merganser

Scientific Name:

Mergus merganser




Freshwater lakes, rivers, and ponds in northern forests.


Common mergansers are found throughout much of North America and Europe.


Least Concern (IUCN Red List)

This species is


to the Truckee Meadows.


For a bird with “common” in their name, they sure have a lot of nicknames! Their nicknames include “sawbills” because they have a thin sharp red bill with pointy “teeth” or serrations (to better hang onto fish), “fish ducks” because they eat fish, and “goosanders” (latin for plunging goose) because they spend so much of their time diving or submerged. Common mergansers are large ducks, significantly larger than hooded mergansers. Common mergansers may weigh up to 4.75 pounds, with a height of just under 28 inches, and a wingspan just under 34 inches. Male common mergansers have an iridescent dark green head and a bright white body, while the female has a gray body and a rust colored head with shaggy plumage. The diet of common mergansers is mostly fish, with a few shrimp, mussels, frogs and insects. Young hatchlings can feed themselves and begin on a diet of aquatic insects, but progress to fish by twelve days after hatching. Common Mergansers make their nests in large tree cavities (often repurposing woodpecker nests), nest boxes, or occasionally rock crevices.

Fast Facts:

  • An adult male common merganser can swallow a whole fish longer than a foot in length.

  • Female common mergansers may lay some of their eggs in the nests of other common mergansers, hooded mergansers or goldeneye ducks. This practice, along with flocks of up to 75 birds, can leave some new moms with broods of nearly 40 ducklings.

  • Common mergansers are diving ducks, while they normally dive for about 30 seconds, they can stay underwater for up to 2 minutes.



Regina Hockett (research & content)

Erin Larsen (editor)

Last Updated:

March 27, 2024 at 1:48:22 AM

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