Tortoise Triumph: Giant Tortoises Reintroduced to Galapagos Island 

The Floreana Island giant tortoise was thought to have died out 180 years ago. Now its descendants have returned to the island.  

The famed giant tortoises that give the Galapagos Islands their name have been extinct on Floreana since the early 1800s. When whaling boats made port on the island, sailors took tortoises as a source of food for long voyages. This continued until there were no tortoises left, and Floreana was tortoise-less for almost two centuries. The subspecies was presumed completely extinct.   

However, in the early 2000s researchers noted something strange about the tortoises on nearby Isabela Island. The native subspecies on this island has domed shells, but among the tortoises on Wolf Volcano there were some that had saddleback-shaped carapaces, similar to the extinct Floreana tortoises. Genetic analysis revealed these tortoises were the result of interbreeding between the Floreana and Isabela subspecies.  

While the Floreana subspecies had been completely removed from their native island, they had not all died out. The sailors did not kill every tortoise taken from the island. They unloaded some onto Isabela Island for stockpiling and threw others overboard to lighten cargo loads. These survivors persisted, interbreeding with the native tortoises. Moreover, given the long lifespan of giant tortoises and the strength of the genetic similarity between the hybrid tortoises and the Floreana subspecies, some believe purebred Floreana tortoises could still be alive on Isabela. If this is true, they have not yet been found.   

In 2017, 23 hybrid tortoises with the closest DNA match to the museum specimens of the Floreana subspecies were chosen for a breeding programme. As of 2025, this breeding programme had produced 600 hatchlings.   

Several hundred of these hatchlings are now grown enough to survive independently in the wild. At the end of February, 158 were released onto Floreana. They are the first tortoises to set foot on the island in nearly two centuries.  

The reintroduction is part of the Floreana Ecological Restoration Project, which aims to restore 12 missing species to the island. Conservationists suspect the tortoises will play a vital role in restoring the damaged ecosystem, thanks to their role as ‘ecosystem engineers’. Tortoise activity will shape the landscape of Floreana, as they break up vegetation and disperse seeds.  

The Galapagos Conservation Trust has called this a “hugely significant milestone” that provides hope “for the future restoration of islands around the world”.  

Written by Eloise Trawick.

Edited by Kazuma Oura.