Officials in the Upper Mississippi River U.S. Fish and Wildlife Refuge will meet today in Prairie du Chien, Wis., to discuss recent findings which link dying bald eagles and lead ammunition.
Beginning in 2011, U.S. Fish and Wildlife Service biologists Ed Britton, Sarah Warner, Mike Coffey and Drew Becker collected dead bald eagles from Iowa, Minnesota, Illinois and Wisconsin. After testing the livers of 168 dead birds, they found that 48 percent came back with detectable lead concentrations. 21 percent had lethal amounts of lead, indicating lead poisoning.
The lead most likely came from the carcasses of wild game left behind by hunters using lead ammunition. According to a fact sheet by the Iowa Department of Natural Resources, eagles frequently scavenge deer and pheasant carcasses, many of which contain lead fragments left behind by hunters who cleaned the carcasses on-site and left behind gut piles which may contain lead fragments. High amounts of lead can be lethal, and non-lethal exposure can cause vision and respiratory problems, leading to secondary trauma.
Lead is currently the most popular material used in shotgun ammunition because it is dense, inexpensive, readily available and soft enough not to damage vintage gun barrels, a common problem with steel ammunition. Fortunately, companies in the hunting and shooting industry have already created several non-toxic alternatives, including Tungsten-Matrix, which has nearly the same density and softness as lead, key factors hunters look for when choosing ammunition.
The meeting today in Prairie du Chien is part of a series of information sessions being held in Minnesota, Wisconsin and the Quad Cities over the course of two weeks. For more information on these meetings and the effects of lead on bald eagles, visit the U.S. Fish & Wildlife Service.