They used 'Judas goats' to save a dying ecosystem—and the result is a stunning comeback for nature.

In 1997, Galápagos conservationists used sterilised, radio-tracked "Judas goats" to help restore the islands. After more than 140,000 goats were removed by 2006, native plants and wildlife habitat began recovering. This project used clever tracking methods to find hidden herds, which finally allowed the unique island ecosystem to grow again.