Some years they have arrived with their cygnets, and some years the pair have come without a family. Because of winter feeding by Riverside Park visitors and marina residents who supply the swans with whole grain bread, the pair remains at the Boat Basin throughout the winter and leaves for their summer breeding grounds in mid March. The Mute Swans of Central Park remain on the Meer or the Lake until it freezes over and then leave for the winter, returning in March. During a mild winter, like the one we just had, the swans stayed in Central Park throughout the winter. This is not the same pair that live at the Boat Basin.
Aquatic plants are their main food.
Dabbling ducks like Mallards do not compete with the swans, but eat plants that float to the surface from the swans' feeding. The head and neck of the swan is sometimes stained brown from water and mud containing iron. The nesting pair usually maintains a large territory on a small lake or pond, only rarely nesting together in a colony. They vigorously defend their nests and young from intruders. Their nest is a large pile of aquatic plants, sticks, reeds,and roots gathered by the pair of swans on an island in pond or on its banks and lined with down and feathers.