Mallards are hardy ducks, wintering regularly in southern Ontario and southern British Columbia. Some will remain as far north as they can find open water. Even in Alaska, some birds are found throughout the colder months, and in Alberta, Mallards stay on the open waters of the North Saskatchewan River as far north as Edmonton. The great majority, however, migrate to the central and southern United States, where lakes and ponds are ice-free throughout the year. The Mallards are essentially freshwater ducks, although some may winter on coastal bays.
Mallards are one of the first ducks to arrive back on the breeding grounds in spring.
They are adaptable and may nest near a lake, pond, river, or even woodland pool. Their preferred habitats, however, are the natural grasslands that surround little reed-ringed sloughs and potholes on the prairies. By late March or early April, the first of the Mallards are back on the prairies. At this time, lakes and ponds are usually frozen, and only meltwater fills the hollows of pasture lands and fields. The early arrivals are usually mated pairs.