Eight-year study shows lead poisoning in nearly half of U.S. bald eagles

Feb. 17 (UPI) -- A new eight-year study published in the journal Science has found widespread lead poisoning in North American bald and golden eagles.

The study, "Demographic Implications of Lead Poisoning for Eagles Across North America," shows population-level lead poisoning of eagles on a wide scale.

The study evaluated 1,210 bald and golden eagles from 38 U.S. states. According to the study's abstract, it found "unexpectedly high frequencies of lead poisoning of eagles."

Chronic lead poisoning was found in 46-47% of bald eagles and 7-35% of golden eagles.

The study said demographic modeling suggests poisoning at this level surpasses population growth rates for bald eagles by 3.8%.

The study was led by the U.S. Geological Survey, Conservation Science Global, Inc., and U.S. Fish and Wildlife Service.

"This is the first study of lead poisoning of wildlife at a nationwide scale, and it demonstrates the unseen challenges facing these birds of prey. We now know more about how lead in our environment is negatively impacting North America's eagles," said Todd Katzner, USGS wildlife biologist and lead USGS author. 

Eagles get lead poisoning from ingesting it, usually from lead ammunition left in animal carcasses.