Food habits of redheads at the Horicon marsh, Wisconsin

Food habits of Redheads (Aythya americana) investigated at the Horicon National Wildlife Refuge, Wisconsin, during 1983-1985. Prelaying females consumed plant material almost exclusively, primarily seeds of moist-soil plant species. The diet of laying and incubating females was dominated by seeds but also contained 16-17% animal matter. Consumption of animal matter during egg production was substantially lower than reported in other studies of food habits of Redheads. The diet of Juvenile Redheads changed with age. Animal foods were nearly half of the diet of ducklings <4 wk of age, whereas older ducklings consumed primarily plant material. A diversity of flooding regimes may promote plant communities that produce importance food resources for Redheads on the Horicon Marsh.