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Bald Eagles and Lead Toxicity

Discovering the real impact of lead on eagle health, reproduction, and population recovery throughout the northeast corridor

Dr. Brenda Hanley, a mathematician with the Cornell Wildlife Health Lab, has developed population models for bald eagles and determined lead toxicosis has impacted population recovery. This project involved multiple state and provincial agencies, federal agencies, universities, and non-governmental organizations with 31 collaborators contributing intellectual property, population data, and/or expertise. The team produced several manuscripts and online tools, which examine bald eagle life histories over 30 years of recovery in the northeast U.S. and Canada under different hypothetical lead removal scenarios. Using data from thousands of eagles collected throughout the northeast U.S. and Canada, we created a “counterfactual” model to understand what would have happened to bald eagle populations had mortalities due to lead toxicosis not occurred.