The black-necked swan is a large waterfowl native to South America, particularly found in countries like Argentina, Chile, and Uruguay. It is easily recognizable by its striking black neck and white body. These swans typically inhabit freshwater lakes, ponds, and marshes, where they feed on aquatic plants. Black-necked swans are social birds, often seen in pairs or small groups. They are known for their graceful swimming and can be quite vocal, producing a range of honking sounds. During the breeding season, they build nests near the water's edge, where they lay and incubate their eggs.