Northern Prairie Wildlife Research Center
STATUS: Locally common or rare.
HABITAT: Inhabits wooded, clear freshwater habitats, preferably water with sandy, gravelly, or cobbled bottoms. Prefers fast-flowing water, but also uses standing water as long as it is clear, small fish and invertebrates are abundant, and nest sites are available. Easily disturbed and thus tends to avoid areas of human activity. In Wisconsin, brood habitat was described as rivers with high levels of food resources, fast current velocities (0.80 to 0.93 feet/second), and wide (40 to 60 feet) and moderately deep (1 to 2 feet) channels with cobbled bottoms and heavy surrounding cover of mixed hardwoods.
SPECIAL HABITAT REQUIREMENTS: Wooded, clear water streams, rivers, swamps, ponds, and lakes with cavity trees.
NEST: A cavity nester that uses almost any hole or hollow tree, at any height, as long as it is large enough for the female and her nest. The nest tree is usually within a few yards of, or standing in, water. Prefers flooded shoreline with standing trees, and with snags or stumps interspersed but will nest in other locations, including nest boxes.
FOOD: Captures food during short dives in shallow, often rapidly flowing water, or at water surface. Eats small fishes (mainly rough fish), crayfish and other crustaceans, many aquatic insects such as caddis fly larvae and dragonfly nymphs, also some seeds and parts of aquatic plants.
REFERENCES: Bellrose 1976, Johnsgard 1975b, Kitchen and Hunt 1969, Morse et al. 1969, Palmer 1976b, Terres 1980, Vickery in Farrand 1983a.