By their third spring, mute swans reach sexual maturity and mate for life. The breeding pair builds a large nest, about six feet in diameter, of reeds and grasses. Yearly midwinter mute swan population counts in Rhode Island, based on aerial surveys. Charles Allin, F1hode Island DEM, Division of Fisheries and Wildlife. The first sighting of a mute swan in Rhode Island was in 1938, and the first nesting pair was seen here in 1948.
Swans have different personalities, with some being much more belligerent than others.
In general, mute swans behave most aggressively towards other swans, and next most aggressively towards other white birds such as gulls. Swans are least aggressive towards brownish birds like ducks and geese, probably because their own cygnets are brown. Rhode Island Sea Grant researcher J. Stanley Cobb, who studied the mute swans on Rhode Island's coastal ponds between 1978 and 1981, observed great variation in territory-defending behavior. Researchers saw no other waterfowl at the pond. In contrast, another pair of swans frequently allowed ducks to feed within 30 feet of their nest.