Yesterday, a study was published in Science which documents the widespread chronic lead poisoning of bald eagles. The source is lead ammunition fragments found in the gut piles and carcasses of animals killed by hunters. In Wisconsin, almost all these animals would be whitetail deer.
“Almost half of the eagles the team inspected showed signs of repeated lead exposure in their bones, raising concerns about the impacts on bald and golden eagle populations around the continent.”
Bald Eagle photo by Mick Thompson
The level of poisoning is intense and widespread enough that bald eagles' reproduction is less than it should be. The Golden eagle population is smaller and more vulnerable than the Bald Eagles. The poison is an even more fundamental threat to goldens. The poison accumulates over time so the current bad effects on both species will probably get worse.
“Nearly every single eagle we tested had some lead exposure over the course of its life.”
I received a report of how this can happen late this winter. Sally and I allow three folks to hunt deer on our land in Richland County. One of them found a Bald Eagle feeding for several days on a deer carcass on our property. The deer might have been shot on a neighboring property and died on ours or it might have been a road kill. One of our hunters feared that he had wounded a deer but could not find it after a two day search. That might have been the eagle's meal.
Bald Eagle photo by Nigel
Two of our three hunters use lead-free ammunition. I did not think to ask the third. I shall next season but he is an extraordinarily ethical and knowledgeable hunter, who is concerned about the safety of the food his family eats. I hope and expect that he uses non-toxic ammo. I don't know about the group that hunts next door but I'm not so optimistic about their ammo. The point being that there's some chance the eagle was feeding on a carcass contaminated with lead.
We can and should stop this poisoning of our eagles. Copper ammunition is widely available, as effective as lead, and non-toxic. It's more expensive but that will change over time if demand grows. Hunters can practice shooting and sight in firearms with the lead loads and use copper in the field.
My sad guess is that passing these regulations will be difficult in many states, including Wisconsin. I predict we'll hear that the copper ammunition is too expensive and the regulations a curtailment of hunters' rights.
In October 2020, Ron Spomer, one of the most respected experts in outdoor, hunting and fishing journalism on firearms and ballistics for hunters, created a video and article analyzing the differences between copper and lead shot in practice and in consequences. In his words:
“Inadvertent poisoning of scavengers is wasteful and a black-eye on hunters. ”
In our efforts to do what we can until more sweeping changes manifest, we can take the following steps:
Any Madison Audubon member who hunts should use the copper loads for deer hunting with rifles and non-toxic loads for any other small game.
Sally and I are like many Wisconsin landowners. We permit relatives and friends to hunt deer on our land because we think some hunting is necessary for the health of the herd, especially with the rise of CWD, and the overall condition of habitat. With CWD rates rising in Richland County I asked our hunters to try to increase the number of does they killed on our property. Our friends really enjoy hunting on private land and we are happy to provide them that opportunity. And they share some venison with us. Since they are careful to clean the deer properly and have each tested for CWD, we think that's a healthy and delicious food. I bet a fair number of Madison Audubon members do the same. Please ask or require your guest hunters to use non-toxic ammunition for deer hunting (or any other hunting on your land).
Many Wisconsin land trusts, including Madison Audubon, allow deer hunting on their lands—again, protecting habitat and limiting CWD are the two key reasons. Every land trust should require every hunter to use lead-free ammo.
The DNR and any other state entity that allows hunting on its lands should require non-toxic ammunition. So too should the US Fish and Wildlife Service on its National Wildlife Refuges and Waterfowl Production Areas. Some DNR and USFWS lands are in prime eagle wintering spots. There is simply no excuse for those agencies to allow any form of hunting that will expose eagles to lead poisoning on those lands.
We protected eagles from DDT poisoning decades ago. They need and deserve our protection again.
Topf Wells, Madison Audubon board of directors and advocacy committee chair
