The American bald eagle has made a successful comeback since their numbers dwindled due to human pressures in the early 1900s. However, the charismatic national bird continues to be threatened by another human-driven cause: lead.
Dr. Krysten Schuler, wildlife disease ecologist with the Cornell University College of Veterinary Medicine’s New York State Animal Health Diagnostic Center (AHDC), explains how the New York State Wildlife Health Program – a partnership between AHDC and the New York State Department of Environmental Conservation that examines wildlife mortalities – recently discovered that out of 300 bald eagles tested in New York state, 17 percent had lead levels high enough to cause death from lead poisoning.
“While the American bald eagle population has rebounded, lead is still a serious risk particularly to the adult, breeding-age birds. In over 300 bald eagles tested for lead over the last 22 years, we found that 17 percent had lead levels high enough to cause death from lead poisoning, and 83 percent had exposure to lead.
“The impact of lead on wildlife and the environment has been an issue for more than two decades. Despite the federal government instituting a national ban on the use of lead ammunition for waterfowl hunting in 1991 due to an estimated one million ducks and geese dying annually from accidentally ingested lead, lead is still routinely used in some ammunition and fishing tackle.
“The next step is to fingerprint the sources of lead in bald eagle mortalities using lead isotope analysis and collaborate with Northeast states and provinces to conduct a meta-analysis of demographic and spatial data to identify patterns associated with lead poisoning."