Northern Prairie Wildlife Research Center
HABITAT: Inhabits grass-margined wetlands in prairie and forested habitats, with the largest breeding concentrations found in marshes of hardstem bulrush bordering lakes. Winters on sheltered bays, estuaries, coastal marshes, and freshwater lakes, preferring a more sheltered habitat than the greater scaup.
SPECIAL HABITAT REQUIREMENTS: Lakes, ponds, potholes, marshes, and sloughs bordered by grasses.
NEST: Usually nests in upland areas adjacent to water but also on islands, in wet meadows, in shallows at edges of bays and sloughs among bulrushes or on tussocks in marshes. Conceals nest well in hollows on usually dry ground, in grasses, nettles, low brush, even under driftwood.
FOOD: An expert diver, generally feeds in water 5 to 6 feet deep, but may feed to depths of 15 to 20 feet. Consumes plant and animal foods about equally, including seeds and vegetative parts of pondweeds, grasses, sedges, widgeon grass, wild rice, bulrushes, snails and other mollusks, crustaceans, and aquatic insects.
REFERENCES: Bellrose 1976, Johnsgard 1975b, Palmer 1976b, Terres 1980.