Famously, the United States of America once nearly allowed its own national bird to go extinct. In 1963, fewer than 500 breeding pairs of bald eagles (Haliaeetus leucocephalus) survived, following years of poisoning with DDT insecticide. Since agricultural DDT was banned, they have bounced back to more than 16,000 pairs. Understandably, potential threats to these avian icons get taken seriously.
One such threat is a mysterious disease that was first documented in the 1990s along the Wisconsin River, where eagles gather year-round because of the rich fishing opportunities. Wisconsin River Eagle Syndrome (WRES) causes weakness, stumbling, tremors, vomiting, seizures, brain damage and, rapidly, death, although it is not considered an immediate threat to bald eagle populations.
Its cause has remained elusive. But scientists led by Tony Goldberg of the University…