One of our more attractive invasive species is finally coming under fire.
In the summer of 2009, two families of swans that make their home in Brooklyn’s Prospect Park started a turf war.
That year, two adult swan pairs living on the park’s 60-acre lake both began raising baby cygnets, upsetting an uneasy coexistence. Soon, the larger of the two families (one ended up with four surviving offspring, the other only one) began making a move to the lake’s northern shore. During the journey, the dominant male attacked the smaller swan family, looking, as the New York Times’ City Room blog put it at the time, “as if he’s trying to drown them.”
“It’s as exciting as watching a National Geographic documentary,” New York City Audubon Society ornithologist Susan B. Elbin reflected to the Times. But, she reassured, it was “incredibly normal.”
Except for one thing. Those feuding Cygnus olor weren’t actually a natural part of the New York landscape. Mute swans – the storybook animals with orange beaks and long, elegant, curving necks – were introduced to North America during the 19th century by nouveau riche urbanites hoping to impart a bit of old-world beauty to their recently constructed estates. Predictably enough, the wild birds soon flew the coop, spreading in the wetlands from Massachusetts down to Maryland and inland towards the Great Lakes.
Now, the New York State Department of Environmental Conservation has targeted the birds for eradication, pledging to eliminate the approximately 2,200 wild swans that live in the state by the year 2025. The department introduced the plan earlier this winter, and it remains open for comments until mid-February. It names strategies like sterilization, the destruction of eggs, and outright shooting to control the swan population.
Invasive species cases don't typically ignite huge debates that filter out beyond the environmental or planning communities. Few animal activists bother crusading for the basic rights of snakeheads, zebra mussels, or grass carp. Swans, on the other hand, are pretty enough to stir passions. And that's the extremely short version of how the state of New York ended up being accused of plotting a "swan genocide."
Sentiments like these make it far harder to sell swan-control programs to the general public, according to Scott Petrie, a waterfowl researcher and executive director of the Ontario-based research organization Long Point Waterfowl. "If they were the ugly duckling of birds, the outcry would be not even close," he says. "An invasive species is an invasive species no matter what they look like."
For mute swans, environmentalists make a compelling case that the damage they create is more than enough to justify killing 'em all. Adults eat up to eight pounds of aquatic plants a day, uprooting more than twice that in the process and destroying habitats and food supplies of native fish. They’re known for their uniquely territorial behavior during nesting season, and their aggressiveness has helped them out-compete native bird species like Canada geese, loons, and trumpeter swans.
The territorial nature of mute swans has also occasionally brought them into conflict with humans.
Until the last decade or so, many of the dangers that mute swans pose to local environments went relatively unacknowledged. In the late 1980s, New York City’s Department of Parks and Recreation proudly boasted that their wildlife promotion and park cleanup efforts had been successful enough to allow for two straight years of hatchlings from the non-native swans in Prospect Park. In 2002, Hagerstown, Maryland, actually purchased a new pair to live in their city parks after a beloved swan died. (And in fact, they would have sprung for four if two hadn’t flown away before the deal could be made.)
Even today, mute swans have their defenders, from casual bird lovers to ardent animal activists. One of the most vocal opponents of New York’s new plan is David Karopkin, a law student who founded the group GooseWatch NYC. Karopkin first became a bird advocate in the aftermath of the "Miracle on the Hudson" incident in 2009, in which Canada Geese were blamed for the spectacular forced-water landing of US Airways Flight 1549. He now says he worries the mute swan is under a similarly unfair attack, and has a petition that's already racked up more than 20,000 signatures. “Humans are the worst perpetrators [in the environment]. I don’t think there’s any way mute swans can compare to the harm we do,” he says. With species deemed invasive, he thinks it's too easy to make the case. “A bird could poop and we would want to kill it.”
When Maryland’s Department of Natural Resources began targeting the Chesapeake Bay’s swans in the early 2000s, animal activists put up a multi-year fight that brought them through both the federal court system and Congress. Though they lost the case – new legislation effectively removed the mute swan and other non-native species from the protection of the Migratory Bird Treaty Act – many still object. In 2009, the Humane Society published a fact sheet on the mute swan that points out how much greater the environmental devastation of factories, boating, and rampant development has been on the ecosystem.
Scientists and government environmental experts in places ranging from Maryland to Michigan have already decided it is worth going down the path that New York is now pursuing. Before the fight began there in 2003, Maryland’s Department of Natural Resources estimated that there were about 3,600 swans living in its portion of the Bay. By 2010, they had driven that number down to about 200. In the last decade, state and local governments have launched similar campaigns in Connecticut, Michigan, and, now, New York.
While the idea of mass killings of swans may be unsavory, more cautious approaches aren't a real option. As Petrie explains, "If they went in and killed 100 a year, you’re going to be killing 100 swans a year for the next 100 years."