By Brooke Kansier
Capital News Service
Bald Eagles are exposed to lead fragments when they feed on gut piles left by hunters.
Hunting is killing Michigan wildlife — and not just in the way you think.
It’s because a toxic metal — lead — has been a hunting staple for centuries. Despite being removed from products like paint, gasoline and pesticides, lead remains popular for shot and bullets due to its malleability and tendency to fracture, making for bigger wound tracks and faster kills.
That fracturing has its downsides, however. Lead fragments in gut piles — left behind when hunters lighten the load to carry their kill out of the woods — can put wildlife at risk of ingesting remnants of the toxin, according to the U.S. Geological Survey National Wildlife Health Center in Wisconsin.
In Michigan, the recovering bald eagle is at particular risk, said Tom Cooley, a state Department of Natural Resources wildlife biologist and pathologist.
“What happens is the eagles are feeding on gut piles from harvested big game. And they’re picking up very fine lead fragments. What happens is a lead bullet will fragment, and if you look at it, it’s a little like a snowstorm,” he said.
“We do find the pieces in the stomachs and it’s very fine, almost to where you’d have difficulty detecting it if you didn’t know it was there,” Cooley said.
Fragments can travel as far as 18 inches from the bullet path, and one bullet can break into hundreds of tiny shards.
Despite the size, they’re deadly, said John Bruggink, a biology professor at Northern Michigan University.
“It only takes a small number of pellets, two or three, to be lethal to many birds,” he said.
Cooley said lead poisoning is the third-leading cause of bald eagle death, behind general trauma and vehicular trauma. While the population is trending upward, so is the percent of lead poisoning deaths.
While Michigan loses more eagles to cars than lead poisoning, Cooley said it’s plausible that eagles hit by vehicles are more likely to be found, while those dying from lead poisoning can go into seclusion and go unreported. He said that could potentially slant mortality numbers.
“That’s a legitimate argument, because if you see the condition of these birds that die chronically, they lose condition, they’ve been off feed,” he said. “It would be easy for it to wind up somewhere people wouldn’t see it.”
In birds like eagles, lead poisoning is a chronic disease, according to the Geological Survey. Symptoms can include lethargy, weakness, inability to fly and progressive emaciation.
These impacts on birds aren’t a new problem. In 1991, the U.S Fish and Wildlife Service banned lead shot in hunting migratory waterfowl nationwide.
Since then, many states — including Ohio and New York— have additional lead restrictions for hunting waterfowl and bird species.
Others give hunters incentives for using non-toxic ammunition or more responsibly managing gut piles from their kills to keep lead away from scavengers. That can be turning in gut piles at designated checkpoints or burying them.
In Utah, for example, hunters who turn in gut piles are entered into a raffle for a rifle or all-terrain vehicle. Arizona has been successful with a similar raffle program that also provides free non-lead ammunition.
In 2013, California became the first state to pass a statewide phase-out of lead ammunition, with it fully banned by 2019. This was to protect the California condor, a critically endangered species with less than 500 members.
Drew YoungeDyke, field and public relations manager for the Michigan United Conservation Clubs, said additional restrictions or a ban to protect the eagle and other species in Michigan likely wouldn’t sit well with hunters.
“In order for something like that to ever be successful, you’re going to have to have buy-in from hunters,” he said. “And I think it’s something that, if you’re looking at voluntary measures, you may be able to get some buy-in.”
He said more public education about the problem is the best way to address the problem.
There’s little agreement on a final solution, however.
Bruggink said he would like to see some form of voluntary or phased-in state program to mitigate environmental damage.
“It would be nice to move toward more and more non-toxic shot, just so that we’re not putting so much lead out into the environment,” he said. “There are more no non-toxic shot alternatives out there than there used to be, and use of those should be encouraged.”
Lena Spadacene, manager of the Humane Society of the U.S.’s Lead-Free Wildlife Campaign in Washington, D.C., said public education and voluntary measures aren’t enough to solve the problem in the long run.
“I think it’s a good step in terms of getting the word out and letting hunters know that this should be taken seriously, for their health and the health of the wildlife they care about,” Spadacene said.
“But lead is so toxic and there are non-lead alternatives — it just makes sense to go the mandatory route, especially because we’ve seen in places like Arizona, most hunters want to do the right thing,” she said.