In early summer, they build their nests, often on the ground. Females seem to choose the same sites year after year. The females lay between three and eight eggs, and then incubate them. This means they sit on the eggs, keeping them warm, and leave only to eat. When incubation begins, the male ducks leave.
Ducklings begin learning to swim and catch food within a day of hatching.
They are able to fly at about 1 to 2 months of age. Hunting Hunting Harlequin ducks is now illegal in the Atlantic Provinces, Ontario, Quebec, and in the eastern United States, where most Harlequin ducks spend the winter. Unfortunately, hunting is still a serious problem. Many Harlequins are shot by mistake, because the females and young ducks look a lot like other, legally-hunted ducks. In addition, the colourful male plumage makes them tempting targets for trophy hunters.