After reaching critically endangered population levels in the mid-20th century, bald eagles continue to steadily rebound across the US. But hunters still pose a major problem for America’s mascot—it’s not the poaching, necessarily, but their bullets used on other animals. Specifically, lead ammunition.
According to a 2022 study published in Journal of Wildlife Management, bald eagle population gains across the nation are stunted as much as 4 percent every year due to lead poisoning. This isn’t from being shot, but because the birds of prey accidentally ingest bullet fragments while eating leftover animal gut piles and carcasses left out by hunters. Speaking with The Pittsburgh Post-Gazette over two years’ later on July 11, one wildlife rehabilitator says lead poisoning still accounts for as much as one-third of all their center’s casework.
[Related: Everything you think you know about bald eagles is wrong.]
“From the rehabbers’ perspective, the overall eagle population is strong, but we have environmental issues going on and we are concerned,” Carol Holmgren, principal licensed wildlife rehabilitator and executive director of Pennsylvania’s Tamarack Wildlife Center, told the paper on Thursday.
Because the raptors are more affected by lead than other scavengers, digesting the heavy metal quickly metabolizes it into their bloodstream and organs. From there, it can wreak havoc on their nervous, digestive, and muscular-skeletal systems—along with impairing brain, kidney, and liver functions. And since a lead fragment as small as a grain of rice can kill an eagle, the majority of lead poisonings prove fatal.
While these deaths thankfully aren’t enough to endanger bald eagle populations alone, they still pose a potentially higher problem across Northeastern states, where poisonings were potentially a percentage point higher than the national average from 2006-2016. The Pennsylvania Game Commission bolstered this possibility with its own study after finding lead in 30-percent of over 200 bald eagles during that same time period. This is particularly troubling given a national ban on using lead shot to hunt waterfowl has been in effect since 1991. Many additional and expanded ammunition bans, however, have consistently remained stalled due politicization and divisiveness.
“Since then, there has been no change in eagle mortality due to lead toxicity,” a PA Game Commission brochure explains.
Treating bald eagles for lead poisoning is a financial burden on rehabilitators, too. According to the Post-Gazette, costs can reach $3,000 per bird in the first month followed by $2,000 each subsequent month during their lengthy healing process.
To help lessen lead’s impact on bald eagle health, experts recommend hunters try to switch from lead-based ammunition and fishing tackles as much as possible—while more expensive in the past, they are increasingly affordable. If hunters do continue to opt for lead bullets, conservationists also urge them to bury their game’s remains and gut piles, which can deter eagles and other scavengers from eating them.
