But one species of swan, Cyprus olor (Mute Swan), is wreaking havoc on its ecosystem. Though it is beautiful, the invasive species must be managed in a careful and responsible way to avoid the devastation of native species and the Chesapeake Bay region.
The Mute Swan is native to Europe and Asia, but is found in North America throughout the Chesapeake Bay area, mainly in Maryland, Virginia and the Susquehanna River Valley of Pennsylvania.
In the 1800s, many developing American cities expressed their civic pride through the creation of public gardens, with intricate paths and large, beautiful ponds. The ponds were decorated with Mute Swans brought from Europe, and their wings were clipped to keep them in the parks. These swans have a very high reproductive rate, a complete lack of natural predators, and an abundance of suitable wetland habitat, causing the species to become quickly established on the Atlantic Coast.
Mute swans can eat up to eight pounds of grass each day, severely damaging the grass beds in the Chesapeake Bay region. When the swans feed, they pull out the plant, along with its roots and rhizomes, killing entire communities of vegetation. Because Mute Swans are a yearlong presence, in the cold, winter months, the swans will often eat wheat and other grain from farm fields. These feeding habits damage the Chesapeake Bay ecosystem, and leave less available food for native swan species, such as the Trumpeter Swan. They are also fierce, territorial creatures that will attack humans under stressful conditions.
So how can professionals manage these destructive, aggressive creatures?
In 2003, the Maryland Department of Natural Resources released the Swan Management Plan. The plan is a cumulative study on the impacts of the mute swan. The plan provides management techniques and objectives to control this invasive species. Scientific evidence has shown that lethal action must be taken against the creatures to protect the Chesapeake Bay area. Non-lethal techniques, such as harassment, behavioral modification, and birth control can only be effective in very specific situations and are generally beyond the DNR’s available resources.
Though swans are beautiful creatures, what the mute swan has done to its ecosystem is anything but beautiful, and the species must be controlled using lethal measures that save its habitat and innocent native counterparts.