The young tortoises, aged between eight and 13, were bred and specially selected to try to reintroduce an extinct species into the wild. They carry 40–80 percent of the genetic makeup of Chelonoidis niger – a species that has been virtually extinct for 150 years.
Two centuries ago, there were around 20,000 giant tortoises on Floreana. Human exploitation and a giant fire caused them to become extinct.
The tortoises that have now been released are the first of 700.
They are large enough to be released and can defend themselves against introduced animals such as rats and cats, says Freddy Villalba, director of the Galápagos National Park breeding center.
