Wood duck
Aix sponsa
L 13½″ W 28″
Habitat: Wood ducks are associated with bottomland hardwood forests where trees are large enough to provide nesting cavities and where water areas provide food and cover requirements (McGilvrey 1968). Requirements may be met in several important forest types, all of which must be flooded during the early nesting season: (1) southern flood plain, (2) red maple, (3) central flood plain, (4) temporarily flooded oak-hickory, and (5) northern bottomland hardwoods.
Nest: Optimum natural cavities are 20 to 50 feet above the ground with entrance holes of 4 inches in diameter, cavity depths of 2 feet, and cavity bottoms measuring 10 × 10 inches (McGilvrey 1968). Management for cavities more than a half mile from water is not recommended, and dead trees, other than cypress, do not usually contain usable cavities. Good densities of suitable wood-duck cavities have been recorded for many timber types (Bellrose 1976). Nest boxes are readily used by wood ducks, and their use may increase breeding populations, even if natural cavities are abundant, if predators are excluded. Measurements and placement of wood duck boxes have been well described (U.S. Fish and Wildlife Service 1976, Bellrose 1976, McGilvrey 1968).
Food: Wood ducks consume large quantities of acorns, usually in flooded bottoms. Other mast and fleshy fruits also are eaten, as are waste corn and wheat (Bellrose 1976). Smartweed, buttonbush, bulrush, pondweed, cypress, ash, sweet gum, burweed, and arrow arum seeds are used by breeding birds. Skunk cabbage, coontail, and duckweed are also food items. Duckweed is also habitat for invertebrates in the diet (Grice and Rogers 1965).