Mute Swans remain with their partners for life. After the age of 2, they create large nest mounds at the side of lakes and rivers, using reeds, grasses, fallen branches etc. The male collects the materials and the female makes the nest, which they can return to each year. In late April, early May, the female lays her eggs (up to seven in total). They both take turns to incubate the eggs, and about 37 days later they hatch. Mute Swans will aggressively defend their nests during the breeding season. They hiss and raise their wings. If they attack, they use their beaks and hard bony spurs on their wings. The young, known as Cygnets, stay with their parents, until their brownish feathers turn white, and in time they are chased away by their parents.

They eat mostly aquatic vegetation, and also some insects, and tiny fish and tadpoles.