The Long Tailed Duck has white underparts, but the rest of the plumage goes through a complex moulting process. The male has a long pointed tail that is up to 15 cm long, and a dark gray bill that has a pink patch on it. In the winter, the male has a dark mark on his cheek and a white head and neck, his breast is quite dark, and he has a mostly white body. I knew these ducks as Oldsquaw Ducks when I was a youngster.
In summer, the male Long Tailed Duck has a dark head along with his neck and back, there is a white cheek patch and a very white ring around his eyes. The female Long Tailed Duck has a brown back and a short, pointed tail. In winter, her head and neck are white with dark on top. In summer, the head is all dark. Juveniles resemble adult females in winter plumage.
They reach sexual maturity by the age of 2. They begin to court in late winter, but usually, do not form pairs until early spring. The male will try to attract a female by shaking his head back and forth lifting his long tail high in the air, and calling with his head pointing to the sky.
They breed in the tundra where there are lots of ponds and marshes, but sometimes you will see them nesting in large mountain lakes that can be found along the North Pacific coast. The nest is usually located on the ground on the edge of a pond. It is built out of vegetation and lined with her down. These ducks are migratory and return to winter along our North Pacific coast.
The young leave the nest shortly after hatching and learn to swim and dive quite quickly. Young are tended by the female but feed themselves from the get-go, you can see them feeding on items dislodged to the surface by the diving of the female as she dives to feed. They can fly by the time they are 40 days old.
The long-tailed duck commonly forms large flocks in winter and during migration. They feed by diving for clams, crustaceans, and small fish. Although they usually feed close to the surface, they are capable of diving to depths of 140 meters. They are the only ducks that use their wings to swim as they dive, this allows them to dive much deeper than other ducks.