CEID members Christopher A. Cleveland and Michael J. Yabsley were authors on a recent study revealing that Trichomonas gypaetinii, a parasitic protozoan, is widely present in Bald Eagles across the United States, affecting nearly 88% of the birds sampled. This parasite, primarily known to infect vultures in Europe, was detected in Bald Eagles, though none of the infected birds exhibited signs of disease or related lesions. Interestingly, the parasite was not found in Golden Eagles, despite similar sampling efforts, suggesting that this species may not be as susceptible.
Researchers collected samples from 133 Bald Eagles and 7 Golden Eagles over a six-year period, using molecular testing to confirm the presence of T. gypaetinii. The study covered eagles from 11 U.S. states, with consistent findings across different regions and age groups. Although the parasite was prevalent, it did not appear to cause illness, prompting scientists to consider the possibility that Bald Eagles may have developed some level of tolerance or resistance to the infection.
Despite the lack of clinical disease in the sampled eagles, the study raises important questions about how T. gypaetinii spreads, especially given its high prevalence in adult eagles. It is suspected that transmission could occur from parents to offspring, but more research is needed to confirm this. As Bald Eagles have recently recovered from near-extinction in the U.S., identifying emerging parasites like T. gypaetinii helps wildlife experts monitor potential future threats to this iconic species.
Please find the paper published in Journal of Wildlife Diseases here.