Wood ducks (Aix sponsa) are one of North America’s most visually striking waterfowl species, recognized for their vibrant plumage and distinctive crests. These ducks primarily inhabit wooded wetlands across the eastern and central United States. Their diet is crucial for their energy levels, reproductive success, and overall well-being.
Primary Natural Diet
The wood duck’s diet is largely plant-based. Acorns are a significant portion of their diet, especially in fall and winter, sometimes making up 75% of their winter intake. These energy-rich nuts, often from oak species, provide carbohydrates and fats for colder seasons.
Beyond acorns, they consume a variety of seeds from trees and moist-soil plants. Maple samaras, elm seeds, and seeds from plants like smartweed, wild rice, pondweeds, duckweed, and sedges are commonly eaten. Seasonal fruits, such as those from dogwood, tupelo, elderberry, black cherry, and wild grapes, also contribute to their diet when available. This diverse array of plant matter ensures a steady supply of energy and nutrients, supporting their daily activities and physiological needs. Wood ducks may also forage in agricultural fields, consuming waste grains like corn, wheat, or rice when natural food sources are scarce.
Supplemental Foods and Seasonal Variation
Wood ducks are omnivorous, supplementing their diet with animal matter, particularly invertebrates. These supplemental foods include various insects (beetles, flies, larvae, dragonflies, ants), crustaceans (crayfish, small crabs, shrimp), and mollusks like snails. The consumption of these animal foods varies significantly with the seasons and the duck’s life stage.
Invertebrate intake increases notably during the spring and summer, especially for females during the egg-laying period. Female wood ducks can increase their invertebrate consumption to as much as 80% of their diet to meet the elevated protein requirements for egg production. Ducklings, too, rely heavily on invertebrates for the first few weeks of their lives, as the high protein content supports their rapid growth and development. After the breeding season, the diet shifts back towards a higher proportion of energy-rich seeds and plant materials.
Foraging Habits and Habitat
Wood ducks forage primarily in shallow water or on land. They are dabblers, feeding by taking food from the water’s surface, submerging their head and neck, or occasionally up-ending their bodies. These ducks rarely feed in water deeper than 18 to 20 inches (45-50 cm), preferring shallower areas. When foraging on land, they often walk under trees to find fallen nuts and seeds.
Their preferred habitat directly influences the availability of their food sources. Wood ducks thrive in forested wetlands, swamps, freshwater marshes, beaver ponds, and along streams and rivers. They seek out areas that offer a blend of open water and dense vegetative cover, often favoring mast-producing hardwoods located near water bodies.
An ideal foraging environment includes a mix of 50-75% vegetative cover and open water. Water depths of 8 inches (20 cm) or less are considered optimal for their foraging activities. The close proximity of nesting cavities in trees to water sources is important, as newly hatched ducklings must quickly reach the water to find food.