This diving duck winters in large flocks on lakes, bays and coastal estuaries where it eats aquatic vegetation, insects, and other invertebrates. During the summer it nests in marshy areas and open grassland lakes. The nest is hidden in low but thick vegetation in shallow water and made from surrounding plants and lined with feathers. Females often make no nest and become brood parasites by laying their eggs in the nests of other Redheads or sometimes other duck species.
The four-digit banding code is REDH.