Mallard ducks are a common and widespread species known for their adaptability across various environments. These familiar waterfowl exhibit an opportunistic omnivorous diet, consuming a wide range of foods depending on availability. Their diverse feeding habits allow them to thrive in various habitats, from urban parks to remote wetlands, a key factor in their global distribution.
Plant-Based Food Sources
A substantial portion of a mallard duck’s diet consists of plant matter. They consume various forms of aquatic vegetation, including the leaves, stems, and roots of plants such as pondweed, wild celery, duckweed, and water lilies. Mallards also eat seeds from wild grasses, weeds, and cultivated crops like corn, wheat, barley, and rice, particularly in agricultural areas.
Acorns and other tree seeds are part of their intake during certain seasons. Berries and other fruits can supplement their diet when available. Their ability to digest seeds, even passing some undigested seeds that can later germinate, contributes to seed dispersal in their environment.
Animal-Based Food Sources
Mallard ducks supplement their plant-heavy diet with animal-based food sources, which provide essential protein. They consume a wide array of aquatic invertebrates, including insect larvae like mosquitoes, caddisflies, midges, and dragonflies. Terrestrial insects such as grasshoppers, beetles, and other arthropods are also part of their intake.
Other animal prey includes snails, slugs, small crustaceans like freshwater shrimp, and worms. Occasionally, mallards consume small fish, fish eggs, or tadpoles when available.
Dietary Variations and Influences
A mallard’s diet changes based on seasonal availability and specific life stage needs. During spring and summer, when insects are abundant, mallards, especially breeding females, increase their intake of protein-rich animal matter like aquatic invertebrates for egg production and molting. As fall and winter approach, their diet shifts to focus on energy-rich carbohydrates from plant materials, such as seeds and grains, to build fat reserves for migration and cold weather survival.
Habitat also plays a significant role. Mallards in marsh environments might consume aquatic plants and invertebrates, while those in agricultural regions forage on waste grains like corn and wheat. Young ducklings require a higher protein diet, primarily consisting of aquatic insects, to fuel their rapid growth, gradually incorporating more plant seeds as they mature.
Foraging Methods
Mallard ducks employ distinct foraging methods. A characteristic behavior is “dabbling,” where they tip their bodies forward in shallow water, submerging their heads and necks while keeping their tails upright. This allows them to sift through water and mud using their specialized bills to locate submerged vegetation, seeds, and invertebrates. They can also “upend” to reach food just below the surface.
Mallards also graze on land, plucking seeds and feeding on grasses and other vegetation in fields or along shorelines. They may probe through mud and wet soil with their bills to find insects and other small creatures.