Most U.S. eagles suffer from lead poisoning, study suggests
The majority of adult bald and golden eagles carry high levels of lead, which derives from hunters’ ammunition, a large study found.
Most bald and golden eagles in the United States have been repeatedly exposed to lead throughout their lives, new research shows. The primary source of exposure is ammunition—as eagles scavenge on the carcasses of animals shot by hunters, they can ingest lead fragments from rifle rounds and shotgun pellets.
In the study, published February 17 in the journal Science, researchers examined lead levels in 1,210 eagles across 38 states—the biggest effort of its kind to date in North America. They found that more than half of the adult birds had bone lead concentrations above 10 parts per million, which pathologists define as chronic lead poisoning.
This level of lead poisoning is slowing the population growth rate of both