Eagles, other species and lead poisoning

Posted on: October 26, 2017 | Bob Frye | Comments

The problem is obvious. The solution is not.

But don’t be surprised if hunters, in the long term, have to adapt.

Pennsylvania’s bald eagle population is large and growing. In the early 1980s the state was home to just three known nests. Now there are at least 250, in more places than ever before, enough that the species is no longer considered threatened.

But it is facing one trouble.

An increasing number of eagles are dying each year from lead poisoning.

What’s happening

The Game Commission has been testing dead and sick eagles since 2006. About one third of those examined died of toxicity, with lead being the most common poison, said its wildlife veterinarian, Justin Brown.

Adult birds suffer more often than juveniles, and females more than males, Brown said. All regions of the state are seeing cases, though, with last year a particularly bad one.

The impact of lead on the birds is bold.

Eagles with lead poisoning typically exhibit muscle loss, are often blind, have tremors and sometimes are discolored from sitting in their own unusually bright green feces.

Treatment is possible, but it’s often unsuccessful, Brown said. Usually, by the time someone finds a sick eagle, it’s too far gone to save.

“It’s one of the more sad and painful things to look at,” Brown said. “You have this extremely powerful bird and when you find them in a field they’re limp, they’re weak. You can pick them up and they don’t even know you’re there a lot of the time.”

It’s not just eagles either. All raptors are susceptible to lead poisoning, he said, because of their relatively powerful stomach acid.

The source

Where the birds are picking up the lead is not entirely clear.

Lead ammunition and fishing tackle is identified as a problem by some, though.

California banned lead ammunition for hunting. A couple of other states are urging hunters to switch to non-lead bullets voluntarily.

Maine, meanwhile, made using lead fishing sinkers shorter than 2.5 inches illegal as of September.

Former U.S. Fish and Wildlife Service director Dan Ashe banned lead ammunition and fishing tackle on all federal lands the day before President Barack Obama left office. The Trump administration reversed that this spring.

Game Commissioners aren’t proposing a lead ban.

But the debate over the safety of lead continues.

Environmental concerns

Sportsmen’s groups typically oppose regulation, saying there’s no evidence ammunition or fish tackle is a significant source of lead in the environment. Meanwhile, some birding and conservation groups continue to push for its elimination.

It’s true that lead ammunition likely remains in the environment after a hunter pulls the trigger, Brown said. Bullets fragment, especially if they hit something hard like bone, he said. Thirty to 40 percent of those fragments can be left behind after passing through an animal, as far as 18 inches away from the impact site.

Eagles and other scavengers can ingest it, he added.

Some of that is surely occurring. Brown said cases of sick eagles and other raptors peak in hunting season.

“Typically, it’s in that mid to late fall and into the winter months,” he said.

But that’s not the only time sick birds show up. Commissioner Jim Daley noted that there were 11 eagles with lead poisoning this summer.

Unless they ate hunter-killed groundhogs, the lead had to come from somewhere else, he said.

“So it’s not just big game hunting,” Brown agreed. “It’s not just one season. We can’t tie it to one thing in particular.”

It could be, too, that more eagles showing up with lead poisoning is simply a reflection of there being more eagles out there and more people reporting them, Brown said.

But, he added, “we are starting to see what we think is an increasing number of cases over time.”

Going forward

So look for lead to remain a hot topic.

For now, the Game Commission is urging hunters to do what they can this fall to protect eagles and other raptors. It recommends burying carcasses and gutpiles or covering them with branches to “make it less likely that aerial scavengers will find and consume the remains.”

It’s also suggesting hunters “consider eliminating lead from their harvests by using non-lead ammunition.”

Will they?

Visit any sporting goods store and boxes of lead ammunition will outnumber non-led options by at least 10 to one. It’s considerably cheaper, too.

The real barrier might be knowledge, though, or rather the lack of it.

“In my communications with hunters, or with the general public, it’s still surprising to hear how many people don’t realize the scope of this issue,” Brown said.

Surely, over time, that will change, if nothing else. We’re in the early days of the lead debate in some ways.

But it’s coming.

Hopefully definitive answers won’t be far behind.

Bob Frye is the everybodyadventures.com editor. Reach him at 412-838-5148 or bfrye@535mediallc.com. See other stories, blogs, videos and more at everybodyadventures.com.

Share This Article

Shop special Everybody Adventure products today!