Wild ducks are adaptable survivors, demonstrating a flexible diet that shifts depending on their location, species, and the time of year. These birds are opportunistic omnivores, consuming a wide variety of both plant and animal matter found within their wetland and terrestrial habitats. Their ability to exploit different food sources allows species like the Mallard, Northern Shoveler, and Canvasback to thrive across the globe.
Aquatic and Terrestrial Plant Sources
The herbivorous component of a wild duck’s diet is fundamental, serving as a primary source of carbohydrates for energy and fat storage. This plant intake includes a variety of submerged and emergent aquatic vegetation. Ducks often consume aquatic plants like pondweed, coontail, and wild celery, focusing on the tubers and roots.
Other species, such as Northern Pintails and Green-winged Teal, focus heavily on the seeds produced by wetland plants, including wild rice and grasses. On land, ducks graze on terrestrial greens, such as grass stems, or consume seeds and waste grain from agricultural fields during colder months. Wood Ducks are known to consume acorns, which provide a calorie-dense food source in forested habitats. This carbohydrate-rich diet is important for building the fat reserves necessary for migration and surviving the winter period.
Invertebrates and Small Aquatic Life
Animal matter forms a second dietary component, providing the protein and fat required for growth, feather production, and reproduction. Wild ducks consume a wide array of aquatic invertebrates, including the larvae of insects such as midges, flies, and beetles, which are often strained from the water column or mud. Snails, slugs, and crustaceans like amphipods are also regularly consumed.
Specialized diving ducks, such as Eiders, swallow mussels whole, relying on the gizzard to grind the hard shells and extract nutrients. Larger animal prey, such as small fish, fish eggs, and amphibians like tadpoles, are also part of the omnivorous diet, especially for diving species like mergansers.
Specialized Feeding Methods
Ducks have evolved efficient methods to capture the diverse foods available in their environments. The most common method is dabbling, which involves the duck tipping its body forward, or “tipping up,” to reach submerged vegetation and invertebrates in shallow water without fully diving. Dabbling ducks, like Mallards and Gadwalls, are often observed with their tails perpendicular to the water surface while foraging.
Filter feeding uses comb-like structures called lamellae located along the edges of the bill. Species like the Northern Shoveler have highly developed lamellae that function as a sieve, straining out tiny seeds, zooplankton, and small invertebrates.
In contrast, diving ducks, such as Pochards and Scaup, pursue their prey deep underwater, using their strong webbed feet to propel themselves to the bottom of lakes or coastal areas to find mollusks, roots, and tubers. Grazing represents a third method, where ducks like the American Wigeon feed on terrestrial grasses and vegetation on land.
Seasonal and Life Stage Dietary Changes
The diet of wild ducks changes in response to environmental availability and the bird’s physiological needs. The most dramatic shift occurs in newly hatched ducklings, whose rapid growth requires a diet dominated by protein, often consisting of 90% or more invertebrates. This high-protein intake is essential for the quick development of muscle mass and feathers.
Adult birds modify their diet in preparation for different life events. Before migration and during the winter, adults prioritize carbohydrate-rich foods like seeds and grains to build fat reserves for fuel and insulation. Conversely, protein demand increases significantly for females during the egg-laying period. To meet the need for amino acids and calcium, breeding females increase their consumption of aquatic invertebrates. Molting, the process of replacing feathers, is also energetically expensive and requires an increase in protein intake, sometimes requiring 30 to 100 percent more protein than normal maintenance levels.