The common merganser is found across Maine during summer and may remain year-round near parts of the coast. Lakes, broad rivers, and other clear waters provide its preferred feeding habitat.
At approximately 22 to 27 inches long, this is a substantial, streamlined duck. Its pointed orange-red bill has serrated edges that help it grip slippery fish underwater.
Large diving duck
About 22–27 inches
Clear lakes and rivers
Narrow, serrated orange-red bill
Identifying males and females
An adult breeding male has a dark green head that can appear black in poor light. The body looks mostly white, with darker upperparts and a clean, high-contrast appearance.
The female has a rusty brown head with a shaggy crest and a gray body. Her ragged head feathers and pointed bill are especially useful field marks. Despite its unusual profile, the common merganser is a duck.
Habitat and behavior
Common mergansers dive from the surface and swim underwater in pursuit of fish. They are often seen alone, in pairs, or in small groups. Clear water makes it easier for these visual hunters to locate prey.
In Maine, suitable waters include inland lakes and rivers as well as coastal areas. Seasonal distribution varies with open water, food, and weather conditions.
Maine observation
The source record documented common mergansers at Giles Pond in Aurora in April 2013, illustrating their spring presence on inland Maine waters.
Range beyond Maine
The species occurs across much of North America. Its distribution changes through the year as birds move between breeding areas and waters that remain open during winter.