After more than five years of tracking Bald Eagle W20 — patient #15-0642, a mature eagle rehabilitated in 2015 — the Wildlife Center staff have confirmed that W20 died, likely due to lead toxicity.
After receiving an abnormal amount of inactivity during last week’s data download, the Center staff carefully scrutinized the data from the GPS transmitter. Based on the lack of movement, along with some other data from the transmitter, the senior research wildlife biologist with Conservation Science Global thought it likely that the eagle had died. After additional discussion between Center staff, Connor, one of the Center’s front-desk coordinators, decided to go out to the area on Sunday, December 6, to see if he could find the transmitter or the eagle’s body. Based on the average of the data points that the wildlife biologist supplied, Connor was able to find the eagle quickly; sadly, the eagle was deceased. He picked up the bird and brought her back to the Wildlife Center for a post-mortem examination.
Dr. Sarah, one of the Center’s veterinary interns, found that Bald Eagle W20 was thin. There were no obvious wounds or fractures; radiographs revealed an irregularly shaped, 2.4 x 3mm metal opacity in the region of the bird’s ventriculus [lower gastrointestinal tract]. A lead test was run on post-mortem fluid in the eagle’s oral cavity, which came back as a high positive. This test is a preliminary test, as it is not the typical way the Center checks for lead on the in-house lead analyzer machine.
Center staff will be working with the Virginia Department of Wildlife Resources, U.S. Fish & Wildlife Services, and the tracking company, Conservation Science Global to coordinate a full necropsy and additional lead testing on biopsies.
Based on the tracking data, the Center staff suspect that the eagle had been doing well until about a week ago and then ingested small lead fragments, resulting in lead toxicity.