While this period varies from year to year, it often follows heavy nighttime rains in late March or early April. Diving ducks nest in New England, Canada, Midwestern and prairie states, the Pacific Northwest and Alaska. Several species inhabit both the Eastern and Western hemispheres. Beginning in winter and before heading north, and into spring, males in their brightly-colored breeding plumage vie for females. Courtship may include ritualized drinking and preening movements, posturing and calling.
Copulation takes place in the water.
Nesting habits and habitats vary from species to species. Generally, female diving ducks lay 5-15 eggs in vegetation, tree cavities, or rock crevices over or near the water. Because females do not start incubating a clutch until they lay their last egg, young develop simultaneously and all hatch at about the same time. Ducklings are covered with down, patterned with shades of yellow or brown to break up their body outlines. Their eyes are open, and they can swim and feed themselves soon after hatching.