Northern Prairie Wildlife Research Center
STATUS: Common; population has increased in recent years primarily because of the availability of artificial nest structures and protection for most of the year.
HABITAT: Inhabits woodlands near shallow, quiet inland lakes, swamps, river bottoms, ponds, marshes, and streams where nest sites are available. Important forest types are central and southern floodplain forests, red maple swamps, temporarily flooded oak forests, and northern bottomland hardwoods. Prefers areas with many perching sites.
SPECIAL HABITAT REQUIREMENTS: Nest holes in trees or nest boxes in or near still or slow-moving water.
NEST: Prefers to nest in natural cavities 20 to 50 feet above ground with entrance holes of 4 inches in diameter, cavity depths of 2 feet, and cavity bottoms measuring 10 by 10 inches. Uses nest trees in (or up to one-half mile from) water 3 to 18 inches deep. Readily accepts nest boxes provided with nesting materials of wood shavings or sawdust.
FOOD: Eats about 90 percent plant material. Forages in ponds, marshes, sluggish streams, or along wooded banks for floating duckweeds, baldcypress cones and galls, seeds and tubers, wild rice, acorns, beechnuts, hickory nuts, grapes, berries, corn, and wheat. Also eats some invertebrates, such as spiders and aquatic insects.
REFERENCES: Bellrose 1976, Grice and Rogers 1965, McGilvrey 1968, Palmer 1976b, Terres 1980.