158 giant tortoises have been reintroduced to a Galapagos Island after they disappeared in the 19th century.
On Floreana Island, a major step in reintroducing the species has begun, carried out by the Galapagos National Park Directorate.
The tortoises released this week were bred and raised at the Fausto Llerena captive breeding centre on Santa Cruz Island, using animals with strong genetic ties to a lineage rediscovered on Wolf Volcano.
According to the environment ministry, the genetic research enabled the breeding program and will allow a phased return of tortoises to Floreana, based on technical criteria.
The ministry added that the release has laid the groundwork for the future reintroduction of up to 12 species considered locally extinct.
It comes after genetic research found that a female specimen discovered on one of the Galapagos Islands three years ago was related to the only previously known example, found in 1906.
There were signs that there may be other tortoises of the same species living with her on Fernandina Island, a pristine wildlife habitat in the Pacific Ocean.
Scientists sequenced the genomes of the 1906 specimen, known as chelonoidis phantasticus, and the 2019 female, who has since been named Fernanda, and compared them with all living species of Galapagos giant tortoises.
They found that the two were linked and distinct from all others, according to the findings published in Communications Biology.
Study lead author Dr Evelyn Jensen, lecturer in molecular ecology at Newcastle University’s School of Natural and Environmental Sciences, said: ‘Only two tortoises have ever been found on Fernandina Island, and here we have shown that they are indeed members of the same species, and different from the other Galapagos tortoises.
‘It is a truly exciting discovery that the species is not in fact extinct, but lives on.’
Fernandina Island is an active volcano at the western side of the Galapagos Islands, which Charles Darwin visited in 1835, inspiring his theory of evolution.