National Geographic : 2007 Sep
WILDLIFE 2°w SReintroduction Area UNITED SSN KKINGDOM Cotswold Hills Cornwall Polden Hills 0mi 150 1 Dartmoor 0 South Devon 0km 150 NGM MAPS Big Blue Is Back In 1979, England's last large blue butterfly - about two inches long-perished. Ecologist Jeremy Thomas watched it die . . . and knew why. Its caterpillars fed on the larvae of a species of red ant that thrived on closely grazed hillsides. But as land use changed, sheep and cattle lost out, ants diminished, and butterflies vanished. Thomas's colleague David Simcox at Dorset's Centre for Ecology and Hydrology rallied volunteers to the cause, bringing back grazing animals and importing caterpillars from Sweden. After a 20-year effort, some 10,000 big blues flitted over the English countryside last summer. -Joel K. Bourne, Jr. PHOTO:DAVIDSIMCOX,CENTREFORECOLOGYAND HYDROLOGY,DORSET,U.K.