Northern Prairie Wildlife Research Center
STATUS: Endangered, numbering fewer than 150 individuals in the traditional wild flock, about 13 in the introduced Rocky Mountain flock, and about 55 in captivity.
HABITAT: Inhabits marshy areas interspersed with shallow potholes having soft marly bottoms and a pH range of 7.6 to 8.3. Primarily inhabits aspen parkland, but also in northern coniferous forest, shortgrass plains, northern mixed forest, river deltas, and tundra. Winters on tallgrass prairies, salt flats, coastal marshes, lagoons, and brackish water areas.
SPECIAL HABITAT REQUIREMENTS: Large, shallow wetlands that provide visibility over a wide area and are free of human disturbance.
NEST: Nests on a mound of bulrushes in shallow water, on islands or along shores of large wetlands where there is a heavy cover of bulrushes. Pairs mate for life, and return to the same general area each year but not to the same nest site.
FOOD: In winter, primarily feeds on blue crabs, but also eats aquatic insects, freshwater minnows, shrimps, crayfishes, marine worms, snails, clams, sprouting corn, acorns, grasses, sedges, and other plants. (Foods of other seasons have not been well documented.)
REFERENCES: Allen 1952, Archibald in Farrand 1983a, Mackenzie 1977, McNulty 1966, Novakowski 1966, Terres 1980.