America's national bird is dealing with a toxic problem.
Research published in mid-February indicates 46% of bald eagles have signs of chronic lead exposure.
Prolonged exposure can be deadly.
"You're going to see a very depressed bird" if you encounter a bald eagle with lead poisoning, according to Victoria Hall, the director of the Raptor Center at the University of Minnesota. "Any raptor that you can walk right up to is not normal. Eagles experiencing lead poisoning might not be able to move. They might just be stuck on the ground. They might be very uncoordinated, they might not be able to see. They look like a sick bird if they have severe lead poisoning."
Experts believe most of the lead is a byproduct of hunting.
"Lead's an extremely soft metal," Hall said. "When it hits things from a rifle shot, it fragments. And it only takes lead the size of a grain of rice to kill an eagle."
The impact on the bald eagle population reflects the effect of lead impact on the overall ecosystem. Exposure has been detected in fish, mammals, and other birds.
Lawmakers are taking note.
California banned the use of lead ammunition for hunting purposes in 2019.
Other states have adopted or are considering bans that are smaller in scope.
"We have a chance to protect this species," Hall said. "A species that almost went extinct in the past, with DDT and other chemicals, that we brought back. We are seeing the signs of another threat to these birds, which is the perfect time to take action to protect them."