Michigan officials are asking residents to help shoot and kill 13,500 mute swans.
But before hunters and fearful lakefront property owners grab their rifles, defenders of the birds are asking for more research to spare the lives of these lake dwellers.
One issue is whether there could be confusion with the swans that are native to Michigan.
“It makes no sense that these swans can’t coexist. The mutes have been here so long and people like feeding and watching them,” said Karen Stamper, a Walled Lake resident and mute swan advocate. “We have more water in our state than most other places in the world.”
Efforts to achieve the state’s long-term goal of killing the birds by 2030 have begun. State employees have killed some and they are letting residents know that with a permit, they can do the same.
All the Great Lakes states report problems with an increase in mute swans that displace native swans and other species, destroy wetlands and even intimidate boaters. Wisconsin and Ohio have killed mute swans in recent years; Michigan has the most ambitious plan yet to kill mute swans.
Michigan also has the largest mute swan population in North America with 15,500, according to the Michigan Department of Natural Resources.
The mute swan is non-native to North America and is increasing in population 9 percent to 10 percent each year, which is causing some big problems, according to Barbara Avers, a waterfowl and wetlands specialist from the Michigan Department of Natural Resources.
They were brought to the U.S. from Europe in the 1800s for their beauty. Some escaped captivity, establishing populations in several states. Michigan’s population began with one pair in Charlevoix County in 1919, according to the Michigan Department of Natural Resources.
One of the biggest problems: Mute swans’ aggression toward humans is increasingly dangerous for people in boats and on shore, Avers said.
“They are considered the most aggressive waterfowl species in the world,” Avers said. “So as we see an increase in the species, we are also seeing an increase in reports about mute swan attacks.”
Although most of the hostile behavior directed at people is bluffing, mute swans can inflict cuts, bruises, sprains and bone
fractures. In at least two cases on the East Coast, mute swan attacks resulted in human deaths, according to David Marks, a wildlife disease biologist with the U.S. Department of Agriculture.
Mute swans keep one of Michigan’s native swan species, the trumpeter swan, from breeding. Both favor similar habitats for breeding and the mute swan begins nesting three weeks earlier than the trumpeter, defending the entire area. The trumpeter swan is on the state’s threatened species list.
“People often say to us that the swans they see aren’t causing any problems,” Avers said.
But some of the problems go below the surface.
Mute swans eat underwater plants. They uproot them, eating far less than what they grab. That destroys the habitat for native species, especially the fish.
“If you have a large flock of mute swans feeding on this bed of vegetation you can imagine that in a pretty short time, they can do quite a bit of damage,” Avers said.
There isn’t a hunting season, but the state allows citizens to register for free permits to shoot mute swans. Such permits first became available in 2006, but with the recent goal of killing thousands of mute swans, the state is re-publicizing their availability.
Permits are also available to destroy their nests, a less efficient method of reducing the mute swan population, Marks said.
With a permit, people can remove nests and destroy mute swan eggs. Although this slows population growth, it does not stop the adult mute swans from continuing to mate.
Stamper, along with other mute swan advocates, dispute the reasons cited for killing 90 percent of the state’s mute swans.
The aggressiveness is just instinct, Stamper said. Humans act the same way when protecting their young.
“I have pictures of a red wing black bird chasing a goose that went too close to its nest,” Stamper said in a letter to a local government agency. “I have a goose going after a swan that was too close to its babies. It’s nature. The same thing happens when a hawk or crow takes a baby from a blue jay, starling, or wren. It does not matter how large or small the animal, they will go after anything that tries to harm their baby.”
She worries that lakefront owners may not distinguish one type of swan from another. Native swans could get killed during the attempt to destroy mute swans.
“If they think there is a swan out there and it shows any kind of aggression or they can’t get their jet ski out, they aren’t going to care if it’s a trumpeter or a mute,” Stamper said. “If it’s in the way, they are going to kill it.”
The most significant difference between mute swans and native swan species is that adult mute swans have orange bills and native swans have black bills. Mute swans also have a black knob on the top of their bill and native swans do not, according to the state’s website.
Although mute swan population control first began in 1960, Stamper started a petition to stop the killing in February 2011. She has received 2,000 signatures and the attention of the state.
“We realize they are a very beautiful species, they are very conspicuous, people come into contact with them a lot and love viewing them,” Avers said.
But eliminating the mute swan is for the greater good of all other things living in Michigan, she said.
Stamper doesn’t believe there has been sufficient research done in Michigan to support that position.
More Michigan-based research is coming.
The U.S. Department of Agriculture Wildlife Services recently received funding to look into some unanswered toxicology questions about the species in Michigan, according to Marks.
The mute swans that have been killed yield useful information, Marks said.
Researchers will be testing for toxics and contaminants to see whether mute swan meat is safe to eat.
“They are not typically a species people eat but we do get asked that question,” Marks said. “If you want to manage your mute swans you can work with the DNR to get a permit and people always want to know, ‘can we eat the meat?’ and nobody here knows how it tastes yet.”
Because mute swans typically feed off the bottom of a lake, which is where pesticides and heavy metals tend to accumulate, Marks feels more research is necessary before humans consume the meat.
Some of the mute swans that have been killed are tested for influenza, Newcastle disease and parasites that cause swimmer’s itch to see if mute swans play a role in transferring these illnesses.
Invasive nonnative species are a longstanding environmental threat. The nonnative emerald ash borer is an example of an invasive species that killed thousands of trees in Michigan beginning in 2002. More recently, the nonnative feral or wild swine’s rapidly increasing population is on the state’s radar. The feral swine hosts parasites that threaten humans, domestic livestock and wildlife.
Marks expects some results from the mute swan research will be available to the public by March of 2013.
And for the people living in Michigan, perhaps mute swan will be on the dinner table by next Thanksgiving.