Unlike dabbling ducks, Ruddy Ducks obtain most of their food by diving to the bottom of shallow pools of water. There they feed on invertebrate and plant matter that they gather by straining mud through a series of plates on their bill. They can sift particles of food from water using a comblike structure on their tongue. They eat aquatic insects, crustaceans, zooplankton, and other invertebrates, along with small amounts of aquatic plants and seeds.
Recorded by Jay W McGowan, Macaulay Library