Giant Tortoise Returns to its Original Galápagos Home

The return of the Floreana giant tortoises to their original home is a win for both the animal and its long-lost island ecosystem. 

The Galápagos Islands are famous for their biodiversity, especially their giant tortoises. But around 180 years ago Floreana Island (part of the Galápagos) lost its unique tortoise, the Floreana giant tortoise (Chelonoidis niger). After it fell victim to the arrival of sailors, pirates and a host of invasive species, it was thought to be extinct. 

In 2000, however, scientists made a shocking discovery: a population of tortoises 70 miles away on Isabela Island looked strikingly like the Floreana giant tortoise with their telltale saddle-shaped shells. Genetic testing confirmed these were hybrid tortoises descended from Floreana giant tortoises that must have accidentally wound up on the island after being put onboard a ship for food.

Now, for the first time in nearly 200 years, tortoises with Floreana ancestry have returned to Floreana Island, following the release last week of 158 individuals reared in a special captive breeding program.

In the carefully managed breeding program, James Gibbs, vice president of science and conservation for the nonprofit Galápagos Conservancy and his colleagues paired adults collected from Isabela Island based on genetic testing to maximize their offspring’s Floreana ancestry. 

While the resulting animals are not exact genetic replicas of their ancestors, they do carry much of the original Floreana lineage, Gibbs says.

In addition to being a win for the animals themselves, the tortoise’s return will also be a boon for the island, Gibbs says. The tortoise is a what is called a keystone species, dispersing seeds and helping to regenerate forests, so the hope is that its return will begin to push the island more closely toward its original ecological state.

It’s a powerful reminder that sometimes what seems lost forever is simply awaiting the chance to return.