Bel Air. -- There comes a moment when a serious environmentalist has to suck it up and kill something.
In England all mute swans belong to the queen, and anyone harming one is liable to penalty. Despite our unseemly fascination with the common behavior of the royal family, we are no longer a crown colony, so nothing except public opinion stands in the way of disposing of the mute swans that have
populated the Chesapeake Bay. Public opinion mistakenly favors the swans, which are large, graceful, white birds that catch and hold the eye.
Maryland's most obvious pair of mute swans spends most of the year in the small pond at the east end of the Bay Bridge, where they serve as nature's billboard, the first tangible proof that one is on the Eastern Shore. If they were the only pair nesting in Maryland it would not matter, but they are part of a much larger problem, one it is time to do something about.
There are currently about 800 pairs of mute swans nesting along the shores of the Chesapeake Bay and its tributaries, the bulk of the population between Dorchester and Kent counties. The numbers have been expanding steadily and inexorably since March of 1962, when, during a storm, five birds escaped from estates on Kent Island.
One pair bred successfully that summer, and by 1980 there were about 400 pairs. Recently mute swans have spread to several locations on the Western Shore and up the Potomac River, and there is no reason to assume the expansion will stop until they have colonized all the suitable habitat in tidewater Maryland. The queen's subjects have always been good at colonizing.
Most people consider the addition of so lovely a bird to the local landscape a good idea. They are wrong. Mute swans, native to the Far East and brought to these shores by way of Europe, are destructive to the habitats of the Chesapeake Bay and to native waterfowl.
Mute swans abuse the hospitality of the Bay in two ways. The first has to do with their eating habits. Mute swans feed primarily on the seeds of underwater grasses. Submerged aquatic vegetation has been closely linked to the health of the Chesapeake Bay. Their disappearance from large portions of the Bay has been implicated in the declines not only in wintering waterfowl, but of the crab and shellfish that at one time made the Bay synonymous with the seafood industry. Unlike most native waterfowl, which nip the seeds from the plants, mute swans rip the plants out by the roots. Because they are large birds, with large appetites, they can strip the submerged aquatic vegetation from large areas of shallow water, making the habitat unsuitable for crabs, fish and other waterfowl.
The second problem is that mute swans are aggressive, especially during the breeding season. They drive other waterfowl, like the fast-disappearing black duck, from the neighborhood, and have been known to kill ducks that were resistant to being moved out.
It is not just the ducks that are being harassed. In Tar Bay, in Dorchester County, there is an island that, until recent years, harbored a colony of least terns and the only black skimmers breeding in the Bay. Black skimmers are listed in Maryland as "threatened," and least terns as "in need of conservation." Mute swans have taken over the island, using it for a molting ground -- a summer haven for birds going through the flightless period when new wing feathers are growing in. The 400 or so swans using the island have driven off the terns and skimmers, birds we are legally obligated to protect.
Waterfowl and Bay biologists are well aware of the mute swan problem. A few biologists even admit that when they find a mute swan nest they shake the eggs, addling them so that no young are produced. This is more effective than removing the eggs, which merely causes the swans to lay a new clutch. Shaking a few eggs, however, is like bailing against the tide, more symbolic than effective, and has done little to slow down the spread of the swans.
The situation has gotten so bad that the state may soon recommend an active program to reduce the swan numbers. When it does, the public outcry will be loud, as it was in New England a few years ago when a similar plan was abandoned in the face of citizen protest. Many animal lovers will leap to the swans' defense, horrified at the thought of these striking birds being killed. Others will resist the proposal because they believe the natural beauty of the swans enhances the scenery. Both groups will be ignoring the environmental realities.
Environmentalism is often about hard choices. On one hand we have a natural (and admirable) opposition to killing wildlife, especially attractive and highly visible wildlife. On the other, we have a proven and serious threat to the Chesapeake Bay and to native wildlife, a threat that is not native, does not belong and can be eliminated. Happy compromises, such as trapping the birds and shipping them to zoos, aren't feasible; the economic and logistical problems are just too great.
Humans have a tendency to feel the greatest compassion for individual animals rather than for species or ecosystems. Sometimes, however, our compassion gets us into trouble, and leads us to make easy choices that feel good today but make no concession to tomorrow. This is one of the times when we have to make a hard choice, but the preservation of the Chesapeake Bay and its native wildlife is paramount. The swans must go.
Eirik A.T. Blom is a biological consultant and free-lance writer.