On the trail of a serial killer

摘要

Our garden frogs have been suffering for years from mysterious illnesses often described as 'red leg' (your many letters to us are testament to this). After a massive study, researchers have finally begun to unravel the truth. How little we know about our native, common frogs became clear 10 years ago when millions died in South-east England in a disease epidemic that raged for a decade and persists today. An investigation into how and why frogs were dying was made possible by public concern and with the collaboration of frog conservationists, a veterinary institute and dozens of dedicated researchers. The result has been described as the most extensive study ever of disease in a wild animal anywhere in the world. Yet joining the trail to trace the suspects was not easy, and proving the case, even harder. Morning sun of an otherwise ordinary day sparkled on the water of an ordinary, back-garden pond in the late spring of 1992. Set in a suburb somewhere south of London the garden had, like the thousands around it, a lawn, neat patio, borders, tubs, shrubs and close-boarded fence. But the frog in the little lawn-edge trench, one of four in view, was not ordinary.