Descendants of the Floreana giant tortoise, a species believed extinct since the 19th century, have been returned to Floreana Island in Ecuador's Galápagos archipelago. In February 2026, conservationists released 158 hatchlings fitted with satellite tracking devices, decades after scientists first found survivors of the lineage on a remote volcano at the other end of the islands.
The giant tortoises of Galápagos are not a single species. Each island historically had its own species, shaped over time by its environment. Several of those species were wiped out entirely after whalers who stopped at the archipelago captured them for food and introduced invasive predators.
The first to disappear, around 1850, was the Floreana tortoise, named for the island where it lived. James Gibbs, vice president of science and conservation at the Galapagos Conservancy and a professor at the State University of New York, told CNN en Español the tortoises had an unusually pronounced saddle-shaped shell found nowhere else on the planet.
How pirates and whalers drove them to extinction
From the 16th century onward, pirates began arriving in the Galápagos, followed later by whalers, sealing the fate of the hundreds of thousands of tortoises that once inhabited the archipelago. Jorge Carrión, director of conservation at the Galapagos Conservancy, an organization that has worked to protect the islands since 1985, told CNN en Español that sailors captured the tortoises because they could survive up to a year without food or water in a ship's hold, meaning fresh meat was available whenever the crew wanted it.
In just two centuries, between 100,000 and 200,000 tortoises vanished from the islands that Charles Darwin visited in 1835 aboard HMS Beagle, a voyage that became central to his theory of evolution.
"Alien tortoises" found on a remote volcano
During a 2000 expedition to Wolf Volcano, the highest point in the Galápagos, at the northern tip of Isabela Island, researchers led by Gibbs found tortoises with an unusual shell shape for the region. Gibbs, who first came to the islands as a university volunteer decades earlier, recalled that thousands of native tortoises lived there, but it soon became clear that some of them looked strange.
In later expeditions the team again found many of these highly sculpted, saddle-shaped tortoises living together in narrow canyons. Gibbs said the researchers called them "aliens" because they did not know what they were. Blood samples sent to geneticists at Yale University confirmed differences from the known local species and the scientists used the same term, alien. Four years later, further genetic studies confirmed the animals belonged to the Floreana lineage.
Carrión said there are two theories for how they ended up so far from Floreana Island. One is natural: heavy rains and flash floods could have swept tortoises between islands. The more likely explanation, he said, involves people. Pirates and whalers routinely carried dozens or hundreds of tortoises aboard their ships, and an accident near Wolf Volcano may have released some. Isabela was also the last checkpoint before ships headed into the open Pacific, where crews weighed their cargo and discarded tortoises if a vessel was over its weight limit.
From egg incubation to release
The Fausto Llerena Tortoise Breeding Center has worked to protect the giant reptiles since 1965, successfully breeding, raising and releasing tortoises from islands including Española and Santa Fé. Nineteen specimens of the Floreana lineage were transferred there for care and breeding after their discovery on Wolf Volcano.
Freddy Villalba, of the Galápagos National Park Directorate, has been a park ranger for 23 years and runs the breeding center. Staff mark and weigh eggs, laid in captivity or collected in the wild, and place them in incubators at different temperatures. Villalba said a tortoise's sex is not fixed at laying but determined by incubation temperature: eggs kept at 29.5 degrees Celsius (85.1 Fahrenheit) produce females, while those at 28 degrees Celsius (82.4 Fahrenheit) produce males.
After four months, the eggs hatch and hatchlings are moved to dark, humidity-controlled boxes for a month, feeding only on their yolk sac to replicate their natural development. They then emerge into enclosures where they eat chopped leaves known locally as "elephant ears" for their first two years. Villalba said hatchlings, measuring just 8 to 9 centimeters, must be carefully protected during this stage because they are easy prey.
Satellite trackers and NASA-backed mapping
In February 2026, 158 hatchlings were released on Floreana Island with satellite tracking devices so scientists could study how they adapt to the habitat and how the habitat responds to them. Using resources from NASA, specialists identified the best release areas, where the tortoises could later nest.
These hatchlings descend from the tortoises found more than 20 years ago on the volcano, which Gibbs said have thrived remarkably in captivity, producing 800 offspring in a short period and continuing to average 60 hatchlings a year.
Walter Chimborazo, a Galapagos Conservancy field assistant at the breeding center, witnessed the birth of the tortoises now living on Floreana Island. He recalled that they were so small, smaller than the palm of his hand. Their release makes him happy, he said, but also brings a bittersweet sense of farewell, since he spent more time at the center than at home and knows he will not see the animals again. His father worked at the same breeding center, and Chimborazo said he takes pride in having raised and taught the tortoises so they could survive on their island.
Hybrid survivors, not pure Floreana tortoises
The recently released tortoises are hybrids, explained Cristian Sevilla, director of ecosystems at the Galápagos National Park. Their genetic makeup is part Floreana tortoise, extinct since the 19th century, and part native species from the Wolf Volcano region.
Gibbs said researchers have not yet found a pure Floreana tortoise but believe they exist, since some young specimens found on Wolf Volcano were 50 percent Floreana and 50 percent a native species, implying a purebred parent. He said it is likely that some pure Floreana tortoises are still wandering the vast volcano, possibly descendants of the originals that whalers brought and left behind. Floreana tortoises can live more than 100 years in the wild.
"Ecosystem engineers"
Carrión described the giant tortoises as ecosystem engineers for the archipelago, helping disperse seeds and shape the plant communities of Galápagos ecosystems. Each giant tortoise eats up to 225 kilograms of vegetation a year, and Gibbs said digesting a single piece of plant material takes about a month, by which time the animal has migrated many kilometers, spreading large quantities of seeds; many plants, he added, do not germinate well unless they have passed through a giant tortoise's digestive tract.
Weighing up to 400 kilograms (882 pounds), the tortoises also act like bulldozers, Gibbs said, digging into vegetation, flattening it and preparing resting spots for the night. Sevilla said that by dispersing seeds and creating open spaces, the tortoises help other species feed and settle, including land birds.
Conservation efforts have already eradicated invasive species such as goats, pigs and donkeys from parts of the archipelago, and are now working to control two further threats, rodents and cats.
A haven for endemic species
The Galápagos Islands have some of the highest levels of endemism on the planet, meaning species found nowhere else. About 80 percent of land birds, 97 percent of land reptiles and mammals, more than 30 percent of plants and more than 20 percent of marine species are endemic to the islands. Carrión attributed this to the archipelago's remote location, nearly 1,000 kilometers (621 miles) from Ecuador's coast, which allowed species to evolve separately from the mainland.
Life there is not without hardship, he added, describing conditions including aridity, water stress, salt stress and UV radiation stress. Gibbs noted that Galápagos wildlife is unusually comfortable around people, and that a rule requiring visitors to keep 2 meters from wildlife exists because the animals do not perceive humans as a threat.
Decades of conservation work
Giant tortoises today survive in the wild only in the Galápagos and on Aldabra Atoll in the Indian Ocean, though they were once among the first megafauna species to spread across Asia, South America and North America, inhabiting areas as far away as Florida until about 10,000 years ago.
The Galápagos have been the site of an extraordinary conservation effort, a collaboration between government, civil organizations and local residents that has bred and released more than 9,000 giant tortoises into the wild over the past 60 years.
Gibbs said the lesson of the tortoises is patience: they grow slowly but are constant and persistent, like the fable of the tortoise and the hare, in which the tortoise wins the race in the end. He added that the animals are so resilient, long-lived and tenacious that they have effectively allowed people to fix some of the problems they created.
