FLOREANA ISLAND, Ecuador — Nearly 150 years after the last giant tortoises were removed from Floreana Island in Ecuador's Galápagos archipelago, the species made a comeback Friday, when dozens of juvenile hybrids were released to begin restoring the island's depleted ecosystem.
The 158 newcomers, aged 8 to 13, have begun exploring the habitat they are destined to reshape over the coming years. Their release was perfectly timed with the arrival of the season's first winter rains.
''They are large enough to be released and can defend themselves against introduced animals such as rats and cats,'' said Fredy Villalba, director of the Galápagos National Park breeding center on Santa Cruz Island, noting that the best specimens with the strongest lineage were selected specifically for Floreana.
These released juvenile specimens, out of a total of 700 planned for Floreana, will be introduced gradually. According to Christian Sevilla, director of ecosystems of the Galapagos National Park, they carry between 40% and 80% of the genetic makeup of the Chelonoidis niger —a species that has been extinct for 150 years.
The lineage of these hybrids traces back to Wolf Volcano on Isabela Island, a discovery that still puzzles scientists today. By selecting adults with the strongest genetic makeup, said Sevilla, the breeding program aims to gradually bring the extinct Floreana species back to its former purity.
Two centuries ago, Floreana was home to approximately 20,000 giant tortoises. However, whaling, a devastating fire, and relentless human exploitation eventually led to their complete extinction on the island.
''In genetic terms, reintroducing a species to that island with a significant genetic component of the original species is vital,'' biologist Washington Tapia told The Associated Press.
Tapia, a researcher and director of Biodiversa-Consultores — a firm specializing in the Galápagos Islands — emphasized that this process is about more than just numbers; it is about restoring a lost lineage.