The Redhead Duck, Aythya americana, is a highly migratory diving duck found across North America. These birds are categorized as a type of pochard, adapted for submerging underwater to find food. Their diet is highly variable and directly reflects the specific aquatic environment they occupy and their current stage in the annual life cycle. The food resources available to the Redhead shift significantly depending on whether they are breeding in the prairie potholes, migrating, or overwintering on coastal bays.
Staple Foods Aquatic Vegetation
The diet of an adult Redhead Duck is predominantly plant-based, especially outside of the breeding season. During the migration and winter periods, submerged aquatic vegetation (SAV) can constitute up to 90% of their total food intake. This high reliance on plant matter makes them unique among many other diving duck species.
The ducks seek out energy-dense parts of aquatic plants, rather than consuming just the leafy greens. They target the roots, rhizomes, tubers, and seeds of various species found in freshwater marshes and coastal estuaries. Common plant foods include the carbohydrate-rich tubers of sago pondweed, wild celery, and the leafy parts of widgeongrass and muskgrass.
When wintering in hypersaline environments, such as the Laguna Madre along the Gulf Coast, Redheads shift their focus to seagrasses. Shoalgrass is a particularly important food source in these coastal habitats, sustaining massive flocks of wintering birds. By consuming the most calorie-rich parts of these plants, the ducks can maintain the fat reserves necessary for survival and future migration flights.
Supplementing the Diet Aquatic Invertebrates
While plant matter forms the bulk of the adult Redhead’s diet for much of the year, aquatic invertebrates provide a necessary supplement of protein and fat. These animal foods are critical for meeting specific physiological demands that plant material alone cannot satisfy. The ducks consume a range of small aquatic life, including insect larvae, small crustaceans, and mollusks.
Aquatic insects, such as the larvae of midges and caddisflies, are a readily available and easily digestible protein source. Mollusks, like small snails and clams, are particularly important because they provide a concentrated source of calcium, which is vital for eggshell production in breeding females. The proportion of these animal foods increases dramatically during certain periods of the year to support high metabolic demands.
How Redhead Ducks Forage and Habitat Specifics
Redhead Ducks are classified as diving ducks, which describes their primary method of obtaining food. They propel themselves underwater using their large feet, with their legs set back on their bodies to aid in this efficient underwater movement. They typically forage in waters ranging from 3 to 12 feet deep, which is shallow enough to reach the bottom where the most desirable plant parts are found.
Once submerged, the ducks use their bills to grub through the sediment and pull up the roots and tubers of submerged vegetation. They may also filter the mud for smaller items like insect larvae and seeds. In very shallow water, they can be observed “tipping up” like dabbling ducks, raising their tails out of the water to reach food just below the surface.
In some instances, Redheads have been observed engaging in a form of foraging known as kleptoparasitism, where they steal food from other waterfowl species. They may surface near American Coots or other diving ducks that have just brought food to the surface, and quickly snatch the item before the original forager can consume it. The specific plant and invertebrate species they consume are determined by their habitat, ranging from freshwater pondweeds in prairie marshes to shoalgrass in coastal estuaries.
Diet Composition Changes by Age and Season
The Redhead’s diet is highly dynamic, shifting significantly based on age and the reproductive cycle. Ducklings have a distinct nutritional requirement for rapid growth, necessitating a diet high in protein. For the first few weeks of life, a duckling’s diet may consist of up to 80% invertebrates, such as aquatic insects and tiny crustaceans.
As ducklings mature, their digestive systems adapt, and they gradually transition to the adult diet, with a greater reliance on plant matter. Adult females also exhibit a dramatic dietary shift just before and during the nesting period. To produce eggs, which are rich in protein and calcium, females increase their invertebrate intake, sometimes consuming animal matter for over half of their diet.
During fall migration and throughout the winter, the focus shifts back to maximizing energy intake to fuel long flights and survive cold temperatures. At this time, the ducks prioritize high-carbohydrate foods like the tubers and seeds of aquatic plants.