CRITTER WATCH: Lovely but ruthless invaders

Although mute swans look elegant on a pond at a park or retirement community, Washington declared them to be deleterious exotic wildlife in 1991 and Oregon has listed the non-native species among the state’s 100 Most Dangerous Invaders list.

Problems in other states prove the birds can spread and multiply quickly, driving away native swans and other waterfowl.

“They are the bullies of the wetlands,” said Jim Gores, Oregon Fish and Wildlife Department invasive species coordinator. “They have a temper and attitude that you would not believe.”

Taylor Bressler, of the Spokane Parks and Recreation Department, said he’d heard stories about nursery school students horrified years ago as they witnessed one of the Manito Park mute swans drowning a duck.

Those swans originated from swans released in Spokane parks in 1984 and 1985. The Manito swans were killed by vandals in 2006. The 1991 state law preventing the importation of mute swans stalled a campaign by local groups to replace the Manito swans.

Despite their genteel appearance, mute swans also are voracious eaters, capable of clearing entire lake bottoms.

As part of a study of mute swan behavior in Maryland, biologists moved two remote-controlled tundra swans near a pair of mute swans.

The mute swans attacked viciously, to the point that one robo-swan lost its head.

Oregon also prohibits the importation of mute swans, and those that are already there must be neutered and have their wings clipped.

But the swans are easily available online — a cursory search of the Internet found a Minnesota woman selling five mute swans at $275 each. And a Chicago company promotes mute swan sales to control Canada geese. Neither of the sites mentions problems with mute swans.

Mute swans are the perfect example of why wildlife officials wish every invasive species was ugly, scary or violent.

This year, a pair of the swans produced cygnets — an obvious violation of the neutering rule — and took up residence at the pond a retirement community, where the residents enthralled by the birds.

“(The swans) are therapeutic beyond belief,” said Irv Elliott, a building manager at Hidden Lakes Retirement Village. “The residents watch the swans — they are beautiful.”

The fact that mute swans are an invasive species doesn’t mean much to the residents. They don’t see the birds causing any problems and the lakes where the birds live are manmade.

So, Oregon wildlife officials backed off, allowing residents to keep the babies as long as they are pinioned and neutered.

But Bob Sallinger, conservation director of the Portland Audubon Society said that, in many cases, allowing invasive species to proliferate will ruin native environments.

“What folks need to understand is that the decision to allow these (invasive) species to exist and proliferate may be the decision to allow another species to decline,” Sallinger said.