Hunters' use of lead ammunition and, at times, its toxic effect on scavenger species like eagles who ingest fragments at kill sites continue to produce news headlines and urgent bulletins from conservation groups.

Yet, evidence of any collective action nationally toward totally banning lead ammunition (and fishing tackle) in favor of safer substances such as copper is in short supply.

California stands as an example of broad action after it banned lead ammo in the California condor's habitat in 2008. Researchers and conservationists had built a case against lead owing to the demise of the condor population, which feeds on carcasses and guts left behind, mostly by hunters using rifles. As little as a gram of lead can be lethal to a raptor. The state went further in 2019, enacting a full lead ban on all hunting.

In Minnesota, the Department of Natural Resources (DNR) in 2021 made its most significant move yet against lead, when it banned its use in hunting in some Scientific and Natural Areas (SNAs) and certain state parks that allow special hunts. That order begins this fall and was a response to a petition from Friends of Minnesota Scientific and Natural Areas and other conservation groups. The petitioners wanted the DNR to require nontoxic shot, slugs and fishing tackle within any SNA and state park that offer fishing and hunting. The DNR rejected the petition, claiming its management powers were limited, but acted nonetheless to reduce the spray of lead in the wild. It added that managing lead ammunition is an issue for the Legislature.

It's Mike McTee's business to understand the ballistics of bullets and how their fragmentation is a source of lead contamination across wildlife species and particularly golden eagles. McTee is an environmental chemistry-educated researcher at MPG Ranch, a conservation organization in Missoula, Mont. McTee also is a lifelong hunter. He grew up as a traditional archer before picking up a rifle when he moved from western Washington state to Montana to enter college. His attention has turned to pursuing bighorn sheep these days.

"I love to be outside," he said, "and when I am hunting I have a goal. If I have to sit on a mountain for six hours just scanning the hillsides, I will happily do that."

MPG's commitment to avian ecology across species has included partnerships with raptor rehabilitation groups, whose patients have included golden eagles sickened by lead. McTee has authored a new book, "Wilted Wings: A Hunter's Fight for Eagles," coming out Sept. 6 that reflects on his enlightenment about the scourge of lead turning up in wildlife food sources and what it might take for more hunters to turn to nontoxic alternatives.

In the interview below, McTee dispelled the merit of a federal ban, even while the U.S. Fish and Wildlife Service has banned lead ammo to hunt waterfowl. McTee said the best approach might be more down-to-earth, in order to keep the stories of wildlife local and relatable. Excerpts have been edited for length and clarity:

What do you make of the Minnesota DNR's position?

If we just magically flip the switch, and say there is a federal ban on lead ammunition for hunting, I don't feel that there is enough inventory of copper ammunition to satisfy the demand. I don't think that would work, so a lot of hunters would not comply, because they would rather not go hunting than comply. But also that means if more people aren't hunting, are there less conservation dollars being generated through the Pittman-Robertson [Act]? And then for a game warden, if you have a copper bullet and a lead bullet, each with a polymer tip, you can't really tell which is which easily. A Berger VLD, which is a lead bullet, has copper gilding metal on the outside which comes to a hollow point, and you don't see any lead on it. So how do you enforce that?

So, generally, there has to be buy-in by the hunting community, but it's happening at a pace that not a lot of people are satisfied with.

The DNR in its own study did ballistics analysis using euthanized sheep. The agency seemed to come at it from a human standpoint — lead in venison — rather than. its impact on wildlife.

I would say the evidence for lead poisoning in wildlife is overwhelming. If you look at exposure in game meat in humans, it is far less compelling. There are studies that it may be higher, but you also are being exposed [to lead] by shooting firearms, particularly indoors. There can be lead in the primer. When people focus on lead in game meats it is probably an easier sell to hunters, but it is less compelling scientifically.

MPG's Bitterroot Valley Winter Eagle Project had landowners watch game cameras focused on carcasses and their use by scavengers. That gave way to you getting hunters involved. They spied 19 scavenger species from mountain lions to wolves to eagles. Is the approach a possible model for educating hunters?

Definitely. We thought, let's take a step back from lead poisoning, and get hunters in western Montana excited about scavengers. Every hunter I talked to was absolutely stoked by what they saw. It just added another layer to the hunters' connectedness to the landscape. You might never see an eagle if you are scanning the forest floor from your tree stand. But when you leave a food source out there, you can see what is out there in the woods you love so much. The idea was to get people excited about scavengers, and if they appreciate scavengers, they understand why lead-free is so important.

I think you suggest that some who are opposed to discussions about nonlead ammo think there is an anti-hunting movement behind it? Does that persist?

I think that is highly variable and it's dependent on geography. On the West Coast, there might be more of that: ''This is coming from an anti-hunting sentiment.'' What I have seen in Montana is none of that. I've talked to thousands of hunters and fewer than 10 have gotten fired up.

How do you get manufacturers on board to make more copper ammo? Can it even be done given the challenges of ammo supply and the perception that copper is less effective?

The point of impact when you change ammo can change, whether you are going lead to copper, or whether it's lead to lead. You need to know whether that bullet will expand at a certain distance. But all these considerations hunters have to take when shooting copper I feel are relevant when they are shooting any bullet, even lead. It is good to know how your bullet will perform.

You write that a way to reach people might be by focusing on population impact at a local level. And yet some in the ammo industry and National Rifle Association say no evidence exists that lead ammo has an effect on a "population level" on wildlife? Plus, the eagle population is healthy.

It just shows how complicated the issue is and how you can take it to support either side, if you believe there are sides here. Since I wrote the book, there have been two studies that have shown that bald eagle populations would be greater without lead poisoning. The population is being slowed because of lead exposure.

When I give a talk about 29 golden eagles that we caught [and tagged] at MPG Ranch and some of them fly to the Arctic Circle or the Yukon or hang around in Montana and then in the winter they come cruising back, that just blows their minds — you see that our actions, wherever we live, can have continental-scale implications. Are we killing birds that can be nesting in the Arctic? That captures my imagination and that of other hunters. It's compelling, and I feel like it builds some compassion for wildlife.