In 1994, at DeGray Lake in the state of Arkansas in the USA, 29 bald eagles were found dead from a mysterious disease. Many more across the area have been found suffering from "Avian Vacuolar Myelinopathy", which causes holes in the brain and spinal cord, and erratic behaviour. Researchers now think they've cracked the mystery, as Eva Higginbotham heard from Timo Niedermeyer at Martin Luther University in Halle, Germany... Like this podcast? Please help us by supporting the Naked Scientists