Inside Region 3
Midwest Region
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Deer offal is an important food source for bald eagles in winter when fishing is curtailed due to frozen waterways/Courtesy of Peter Eyerhalde.

Deer offal is an important food source for bald eagles in winter when fishing is curtailed due to frozen waterways/Courtesy of Peter Eyerhalde.

Hunter Outreach Campaign Reduces Lead Exposure in Bald Eagles

U.S. Fish and Wildlife Service researchers documented in 2012 that lead exposure is a significant mortality factor in bald eagles that inhabit the Upper Midwest Region, including Upper Mississippi River National Wildlife and Fish Refuge (Refuge). Investigation into the sources of lead showed that hunting ammunition, especially deer hunting, was an exposure pathway. A hunter outreach campaign was initiated by staffs from the Refuge and Ecological Services offices in Rock Island, Illinois and Madison, Wisconsin, to reduce the potential for lead exposure in bald eagles and other wildlife.

During winter, bald eagles congregate in high numbers along the Upper Mississippi River. Thousands of bald eagles winter and hundreds of eagles nest on the Refuge annually. On December 11, a record 1,100 bald eagles were present at one location there. Deer hunting also occurs during the peak concentration of eagles, with thousands of hunters utilizing the 200,000 acres that are open to public hunting on the Refuge.

An X-ray of deer offal containing 107 lead fragments. It was collected during a deer hunt on the Upper Mississippi River NW&FR/Courtesy of Saving Our Avian Resources.
An X-ray of deer offal containing 107 lead fragments. It was collected during a deer hunt on the Upper Mississippi River NW&FR/Courtesy of Saving Our Avian Resources.

We examined 58 bald eagles that were found dead in the Upper Midwest Region. Liver lead analysis showed that 60% had detectable concentrations of lead and 38% had concentrations within the lethal range for lead poisoning. Lead ammunition is used by most hunters and often fragments, especially if bone is hit. Offal (gut piles) that would have been discarded on the Refuge was collected from 25 deer that were shot with lead ammunition. Radiographs showed that 36% of the offal piles contained lead ranging from 1-107 fragments per specimen. These results show that bullet fragments embedded in deer offal are a pathway for lead exposure in bald eagles and other wildlife.

It was important to tell this intriguing story to hunters so they would be aware that lead ammunition is an exposure pathway related to bald eagle mortality. Our outreach message was designed to instill in hunters a sense of responsibility as conservationists to reduce lead in the environment through voluntary use of non-toxic ammunition. The outreach campaign was expanded to include the general public, other researchers, organizations, and state DNR partners in Minnesota, Wisconsin, Iowa and Illinois.

Outreach activities varied depending upon the opportunity. Activities ranged from a 30-minute program attended by 10 individuals to a 4-day exhibit at an Outdoors Show attended by 14,000 hunting and fishing enthusiasts with over 700 personal contacts made. We used three primary images in each activity to convey the lead exposure pathway relationship, these included: 58 dead bald eagles lying side-by-side during examination; eagles eating deer offal; and an x-ray of deer offal containing 107 lead fragments.  A total of 645,317 deer were killed with firearms in 2012-2013 in the four states with a corresponding number of offal piles discarded on the landscape.

Each presentation varied depending upon the audience. For hunters, we focused on the Refuge deer hunts held for youth and disabled hunters (quadriplegics, paraplegics and amputees) and progressed into the offal analysis and exposure pathway. Public presentations used several themes, such as “Return of the Bald Eagle”, that included a discussion on management challenges to reduce lead exposure. Presentations given at conferences and to state DNR partners identified the scientific research aspect.

Partnerships were developed to accomplish activities that otherwise would not have been possible. The National Wildlife Health Center conducted liver lead analysis and is currently necropsying an additional 115 bald eagles. Saving Our Avian Resources and American Bird Conservancy funded the purchase of non-toxic ammunition that was provided free to hunters participating in our managed deer hunts. Through partnership with local instructors, we presented at Illinois DNR’s Hunter Safety Education course that is required for youth. Public shooting events are planned for summer 2014 through partnership with the Izaak Walton League to familiarize hunters with non-toxic ammunition and show its performance effectiveness in a casual outdoor atmosphere.

In 2014 we are expanding outreach to furbearer trappers after learning that a Refuge neighbor feeds bald eagles during the raccoon trapping season. He dispatches the live-trapped raccoons by shooting them in the head with a lead bullet, removes the fur, and places the carcasses in a field located adjacent the Refuge. As many as 30 eagles feed on the carcasses daily which are picked clean. After being advised that lead exposure from ammunition is a significant mortality factor in bald eagles, the neighbor stated he will remove and dispose of the raccoon heads before placing the carcasses in the field. Thousands of furbearer trappers in the Upper Midwest Region similarly dispose of animal carcasses on the landscape that are scavenged by many wildlife species.

The success of our outreach campaign is gauged by the comments and actions of those we have interacted with. We have presented to over 2,500 people at 40 venues in addition to several newsletters and newspaper articles. In nearly every presentation, hunters advised they were not aware that lead ammunition could poison bald eagles and stated they would never use lead again. Non-hunting family members stated they would be talking with relatives that hunt and encourage them to use non-toxic ammunition. Landowners stated they would no longer allow lead ammunition for hunting on their property. The provision of free non-toxic ammunition during managed deer hunts in 2012 and 2013 resulted in 25% of hunters not shooting lead. Collaboration with Region 3 Zone Law Enforcement Officer Mary Blasing resulted in non-toxic ammunition being provided to Refuge Officers in Wisconsin and on Refuge Districts in IA, IL and MN to dispatch animals.

By Ed Britton

Researchers examined 58 dead bald eagles and identified lead exposure as a significant mortality factor/USFWS.

Researchers examined 58 dead bald eagles and identified lead exposure as a significant mortality factor/USFWS.

 

 

 

Last updated: April 10, 2014