SOAR

saving our avian resources

SOAR

25494 320th Street

         Dedham, IA 51440              

Phone: (712) 683-5555

Fax: (712) 683-5535

www.soarraptors.org
diversityfarms@iowatelecom.net

Bald Eagles and Lead Poisoning in Iowa

• Below is patient information for the February 2005 - December 2006.
• SOAR set out a trail camera (motion sensitive) in a field with a roadkill deer carcass and recorded diners. Several Eagles scavanged the carcass, as you can see from the pictures below. Eagles returned many times over the course of a week.
• Also we compared xrays from Eagles with lead shrapnel in their stomachs and the xrays of a deer shot with a lead bullet. When a bullet enters the deer, pieces of the lead are broken off from the bones. Eagles apparently eat these pieces of lead, which because of their very strong digestive system, quickly causes posioning.

Eagle Data for Feb. 2004 - Dec. 2006 in IOWA
MacBride Raptor Project, SOAR, and Wildlife Care Clinic

Testing for lead can be done two ways; blood samples and liver samples. While the bird is still alive, blood samples can be taken and analyzed.

Blood lead levels and what they mean:

• Anything under 0.1 ppm is background and is considered normal.
• Anything over 0.1 ppm is considered to indicate exposure to lead, but up to 0.2 ppm would not be poisoning (lethal by itself) and may not require treatment.
• Anything above 0.2 ppm are definite LEAD POISONING cases.

Liver biopsies are completed only after the bird dies.

Liver biopsies and what they mean:

• Anything less then 1.5 ppm is background and is considered normal.
• Anything between 1.5 ppm and 6 ppm is considered to indicate exposure to lead, but not at the potentially lethal poisoning level.
• Anything over 6 ppm are definite LEAD POISONING cases.

Exposure to lead can cause the animal to be impaired and not be able to catch prey, have collisions, etc. so exposure levels are still potentially lethal indirectly.

Bald Eagle Data
Feb. 2004 - Dec. 2006 in Iowa
MacBride Raptor Project, SOAR, ISU Wildlife Care Clinic, & Orphaned and Injured Wildlife, Inc.

This Eagle is scavenging from a deer carcass.
You can see the ribs of the deer. The Eagle is reaching deep into the carcass.
This picture was taken with a motion sensitive trail camera. The carcass and camera were set out in a field in Carroll County in November of 2005. Many Eagles, red-tail hawks, crows and even a rough-legged hawk were photographed feeding off of the deer over the course of a week.

As Eagles seem to seek out deer carcasses the use of solid copper deer slugs would insure the safety of Iowa's wintering Bald Eagles.

XRays

Above: X-ray of a deer carcass that was shot with lead deer slugs, reveals that the main body of the slug traveled completely through the deer, but lead schrapnel fragments were left in the carcass at the points where the slugs passed through and shattered bone. This schrapnel looks quite similar to the irregular schrapnel pieces found in eagle digestive systems. In this x-ray of a deer's mid-section, you can see the lead fragments where the slug went through the ribs below the spine and grazed the top of the spine.

This is an xray of an Eagle. The head is not shown, it would be to the right of the picture. The legs and tail on the left. The white spots in about the center of the photo are pieces of lead shrapnel. This is about where the stomach would be. Eagles have very strong, efficient digestive systems. The lead is usually dissolved in the stomach and sickness occurs very shortly after ingestion. Often, a lead poisoned Eagle will become injured because of impaired nervous system, vision problems and breathing problems caused by the lead.

A note from Kay
Executive Director, SOAR

Please remember that most wildlife rehabilitators operate as volunteers with very narrow budget margins. I understand that the information we have gathered so far is incomplete; an x-ray/blood test/liver biopsy was not done on every single animal. These tests are not free, and we have done the best we could with the resources available to us. I feel that this is enough evidence to point to a problem with lead and eagles, that the most likely source in Iowa during the winter is deer, and that urging hunters to switch to non-toxic copper deer slugs is warranted immediately. I also feel that more scientific research is needed. What are the lead levels in free ranging eagles in Iowa? Lead poisoning and exposure are insidious. Eagles, just like children, can function with lead in their systems, but not at their best level. It may effect their reproduction, longevity, and overall health. What are the long term effects of this? What level of lead are we willing to tolerate in our environment and in our wildlife?

Hunters can show that really care about our natural resources by using non-lead ammunition.

More information:
Bald Eagles in Iowa
Project Gutpile
Lead poisoning condors -cbs news article
www.iowadnr.com - for the complete reports on deer harvest information, mid-winter bald eagle surveys, and fish tissue sampling
www.hawkwatch.org - for a downloadable report on 40 years worth of research on lead poisoning and wildlife and several printable fact sheets on the topic
PDF article - HUNT WG, BURNHAM W, PARISH CN, BURNHAM KK, Mutch B, et al. (2006) Bullet Fragments in Deer Remains: Implications for Lead Exposure in Avian Scavengers. Wildlife Society Bulletin: Vol. 34, No. 1 pp. 167–170