Cygnus olor
Mute swans are large, conspicuous birds typically weighing 20-25 pounds with a wingspan up to nearly 8 feet. Adult mute swans have solid white plumage with a black face-patch and fleshy black knob on top of an orange-colored bill. Juvenile mute swans have white or grey plumage with a grey to pinkish bill. Mute swans hold their neck in an “S” shape, while native trumpeter and tundra swans hold their necks in a “C” shape.
In the United States, mute swans are non-migratory and tend to remain in an area unless the water freezes over or food sources are depleted.
Temperate areas of Europe and across western Asia.
Adult mute swans can be distinguished from other swan species by the orange bill with prominent black knob near the forehead. Native trumpeter and tundra swans have black bills.
Mute swans can impact an entire ecosystem by destroying valuable wetland habitat, dispersing nesting listed birds and reducing the much needed food supply of migrating waterfowl.
The feeding activities of groups of mute swans, regardless of the size of the water body, can cause substrates to become barren (NY DEC 1993). Studies conducted in Rhode Island on mute swan feeding habitat have shown a 92–95% reduction in SAV biomass (Allin and Husband 2000). This reduction in biomass can increase water turbidity, increase soil erosion (Hurley 1991), reduce the reproductive success of SAV and reduce the micro invertebrates, invertebrates, fish and shellfish that are dependent on these plants for food and shelter (Krull 1970). The reduction in SAV biomass also reduces the food supply of migrating birds.
Mute swans are a very large, intimidating bird and can be very territorial, especially during the nesting season. A breeding pair of mute swans can claim a territory of up to 13 acres. Aggressive behavior from the male typically involves chasing an intruder until the intruder leaves the nesting area (Ciaranca 1997). Mute swans have been documented attacking and killing young ducks and goslings that have entered their territory (MD DNR). But in some cases, mute swans will accept the presence of waterfowl nesting nearby. In Salem, an active nesting pair of Canada geese was observed nesting within four meters of an active nesting pair of mute swans (ODFW 2008).