Galapagos tortoise thought extinct for 100 years has been found alive

A single female of the Fernandina Island tortoise species that was thought to be extinct for a century has been found in the Galapagos islands

By Corryn Wetzel

Fernanda, the only known living Fernandina giant tortoise

Galapagos Conservancy

A giant tortoise species thought to be extinct has been found living on the Galapagos island of Fernandina. The discovery marks the first time that researchers have located the Fernandina Island tortoise (Chelonoidis phantasticus) in more than a century.

Biologists located the tortoise, dubbed Fernanda, on the westernmost island in the archipelago in 2019. She is the second-ever tortoise discovered on the island after a single male was collected there in 1906. Fernanda could have been moved from a nearby island by humans, or perhaps floated over in a storm.

Because nearby islands host other giant tortoise species, researchers weren’t sure which species she belonged to. She lacked the distinct saddleback-shaped shell that the century-old male specimen had.

To determine the tortoise’s species, Stephen Gaughran at Princeton University and his colleagues compared her DNA to other known Galapagos tortoises. Using a blood sample from Fernanda and a bone sample from the male specimen now housed in a museum, the team confirmed their genes closely matched and were distinct from the other 13 species of Galapagos giant tortoises.

“We simultaneously were able to show the connection between Fernanda and the other Fernandina tortoise, and also the distinctiveness of those two tortoises from species that we see on other islands,” says Gaughran. “I was surprised, and then once it sank in, I was really excited about it.”

Researchers had found previous evidence of tortoise faeces on the island, leading some to believe that the species persisted. But the volcanic island is uninhabited by humans and difficult to access, making searching for surviving tortoises a challenge. Gaughran is optimistic that there could be other covert survivors on Fernandina Island.

“Our hope is that there are still a couple of other of these tortoises out there on the island. But most likely there aren’t very many of them,” says Gaughran.

If scientists can locate a male of her species, the Fernandina Island tortoises might be able to breed their way back from the brink of extinction.

Fernanda is estimated to be over 50 years old but could live to around 200, giving researchers some time to find her a suitable mate. Until then, Fernanda is living out her days under the care of experts at the Galapagos Tortoise Center managed by the Galapagos National Park Directorate.

Journal reference: Communication Biology, DOI: 10.1038/s42003-022-03483-w

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