Turkey Vultures, Bald and Golden Eagles, Red-tailed Hawks, Common Ravens, California Condors, and other scavenging animals are vulnerable to lead poisoning. They are attracted to hunter-killed carcasses or discarded gut piles and unintentionally consume bullet fragments along with the meat. Other species, such as doves and waterfowl, consume lead pellets or fishing tackle inadvertently while foraging for food. Lead is absorbed as it moves through the digestive tract, causing anemia, decreased digestive function, neurological symptoms, and in severe cases, brain and heart damage that can prove fatal.
We tested this bird’s blood for lead toxicity, and, after repeated error messages, thought our machine might be faulty. We sent the sample to an outside lab and were shocked by what we found. The vulture’s lead level was 6.7 parts per million (ppm)! In people, greater than 0.1 ppm indicates possible lead poisoning. And most birds, such as Bald Eagles, will die with a lead level of over 1 ppm. Yet this vulture was more than six times above what it would take to kill an eagle.
After much work to pass the lead fragments out of the bird’s system, eventually it became clear that the crop (part of the esophagus to temporarily store food) wasn’t passing food, leaving meals and the bullet fragments stuck.
To help them pass, we put the bird under anesthesia and placed a feeding tube and a supportive wrap or “crop bra” to ensure adequate nutrition and move the food through the system. Five days later, x-rays showed that the lead was gone! Within a week, this bird, who had been so dull upon arrival, was growing stronger by the day.
Chelation therapy (the method we use to remove the lead from the bird’s system) lasted two months, and by June, the lead level had dropped to 0.192 ppm. By August, it had decreased to 0.08, and this bird was ready to head to our flight cages where it could stretch its wings and regain strength.
Finally, 123 days after the patient entered our care, it was ready to leave. On a sunny September morning, we drove to the release site near a place we knew dead fish routinely show up, providing an easy food source. When we opened the box, the vulture immediately took off. Within a few minutes, the newly released bird was circling above with another Turkey Vulture, a beautiful sight to behold after a long and winding road to health.
Lead will continue to pose a risk to our wild neighbors as long as we use lead ammunition. Many species are affected, including the highly endangered California Condor, which could return to Oregon after more than 100 years thanks to reintroduction efforts in Northern California. While we are excited for the return of condors, we want to be sure they are adequately protected.
Eliminating the use of lead ammunition in Oregon is a priority for Portland Audubon. There is affordable and effective non-toxic ammunition available on the market right now that would help protect our wildlife as well as hunters families that consume game meat. On July 1, 2019, a full regulatory ban on the use of lead ammunition for hunting went into effect across the entire State of California. Oregon to date has adopted a slower voluntary approach to promoting the transition on non-toxic ammunition.
Regardless of the approach, it is important that there is clear data indicating that this shift is occurring. We have known for more than a century that lead is toxic for birds and it is long past time to get the lead out of our ammunition.