The species have distinctive, colorful plumage. They fly fast and low over the water. All three merganser species breed in Pennsylvania, although their principal range is farther north. Breeding habitat is heavy timber around lakes, ponds, rivers and streams. Hooded and common mergansers usually nest in tree cavities, while the red-breasted nests on the ground, usually in thick cover.
Incubation is by the female and takes about four weeks.
All three scoter species are basically black, with varying amounts of white in the plumage. These sea ducks fly in long, undulating lines, in irregular groups, or in V-shaped flocks. They eat mollusks, crustaceans, aquatic insects and plants. They are rare to uncommon migrants over Pennsylvania, passing through the state in March and April, and again in October and November. Scoters breed in Canada and Alaska.