In a strange scientific discovery, a turtle returned to its native island after 200 years.
A subspecies driven to extinction by hungry whalers is returning after a ‘back-breeding’ program with partial offspring.
The Floreana giant tortoise (Chelonoidis niger niger), a subspecies of the giant tortoise once found in the Galápagos, was driven to extinction in the 1840s by whalers who removed thousands from the volcanic island to provide a subsistence supply during their hunting trips.
Remarkably, 158 young giant tortoises, descendants of the Floreana subspecies, have been returned to the island, a crucial step for the largest ecological restoration project undertaken on the Pacific archipelago.
Giant tortoises, the life-giving engineers of remote ecosystems on small islands, are plodding across the Galápagos island of Floreana for the first time in more than 180 years.
A remnant population of giant tortoises discovered in 2008 on Wolf Volcano in northern Isabela Island was found to be partially descended from the Floreana population.
Most Wolf volcano tortoises had dome-shaped shells like those living on Isabela’s other volcanoes to the south, but some had a saddleback-shaped shell that was more typical of the tortoises that evolved on Floreana.
In 2017, a captive “breeding back” program began, where 23 hybrid turtles most closely related to the Floreana subspecies were selected to reproduce as genetically as close to the original as possible.
By 2025, more than 600 hatchlings had been born, and several hundred were large enough to return to their ancestral island, and the male turtles can grow to almost 1.5 meters in length.
The reintroduction was accomplished through the Floreana Ecological Restoration Project, a partnership between the Galápagos National Park Directorate and a number of charities that work closely with the island’s 160 residents.
An invasive species eradication program, which began in 2023 and has removed most of the rats and feral cats on the island, paved the way for the turtles’ return.
The Galapagos Rail has since been rediscovered on Floreana after not being recorded since Darwin’s first visit, and there has been a revival of populations of ground finches and native geckos, lizards and snails.
Verónica Mora, a representative of the Floreana community, said of the turtles’ return: “This moment marks an important step towards a future where conservation and community well-being go hand in hand, because our livelihoods, from tourism to agriculture and fishing, depend on the health of this island.”
The island’s farmers have also reported greatly improved harvests since rat numbers have been drastically reduced.
Giant tortoises are “keystone species”
Their grazing maintains open habitats, promotes the growth of native plants and creates conditions favorable to reptiles, invertebrates and birds. As they roam, they also spread native seeds across the island.
“Habitats are the foundation for biodiversity, the home where species can move, live and evolve naturally over time,” said Rakan Zahawi, executive director of the Charles Darwin Foundation.
“Giant tortoises are a crucial part of this system. By dispersing seeds, shaping vegetation, creating microhabitats like their well-known mud ponds, and influencing how landscapes regenerate, they help rebuild ecological processes on which many other species depend.”
Hugo Mogollón, the CEO of Galápagos Conservancy, said: “By identifying tortoises on Wolf Volcano with Floreana ancestry and breeding their offspring, we are returning this species to the island in a form that closely reflects its original lineage – and laying a critical scientific foundation for the restoration of Floreana ecosystems and the future reintroduction of additional native species.”
The next phase of the recovery will attempt to bring back species including the Floreana mockingbird, the Floreana racing snake, the vegetarian finch and the little vermilion flycatcher.
Dr. Jen Jones, CEO of the Galapagos Conservation Trust, said: “It is a testament to the incredible efforts we have seen over the past two decades from an entire ecosystem of conservation NGOs, local authorities, determined individual researchers and community champions.”
