A Galapagos giant tortoise belonging to a species long thought extinct has been discovered alive. The turtle is the first of its kind to be discovered in more than a century and has been named Fernanda after her home on the island of the same name.
A single specimen of giant tortoise from Fernandina Island (Chelonoidis phantasticus or “fantastic giant tortoise”) was discovered in 1906. The chance to determine whether the species is still alive came with the discovery of a female tortoise on the same island in 2019.
Stephen Gaughran of Princeton University, USA demonstrated that the two tortoises belong to the same species and are genetically distinct from all others by comparing the genes of the living individual and the museum specimen and comparing them to the other 13 species of Galapagos giant tortoises. He is co-author of a recent paper published in the journal Communications Biology.
The tortoise is different from the others in the Galapagos
“For many years it was thought that the specimen collected in 1906 had arrived on the island from elsewhere because it was the only one of its kind,” said Peter Grant, a professor of zoology and biology and at Princeton who has spent more than 40 for years studying evolution in the Galapagos Islands. “Now it appears to be just one of the few specimens that were alive a century ago.”
“Like many people, my initial suspicion was that this was not a native Fernandina Island turtle,” Gaughran said. “I saw – frankly, to my surprise – that Fernanda was very similar to the one they found on that island more than 100 years ago, and both were very different from all the turtles on the other islands.”
Adalgisei Caccone, from Yale University, said that “finding a living specimen gives hope and also opens up new questions, as many mysteries still remain. Are there more turtles on Fernandina that can be brought back into captivity to start a breeding program? How did Fernandina tortoises colonize and what is their evolutionary relationship to the other Galapagos giant tortoises? This also proves the importance of using museum collections to understand the past.”
All turtles in the archipelago are endangered
“Part of my research is developing a tool that analyzes DNA from ancient museum specimens so we can compare them to modern samples,” Gaughran said. His tool is flexible enough to work on almost any antique specimen. “The software doesn’t care if the material comes from a seal, a turtle or a Neanderthal,” he said.
The only copy of C. fantasticus it was collected by explorer Rollo Beck during an expedition in 1906. Its “fantastic” nature refers to the extraordinary shape of the males’ shells, according to SciTechDaily.
The generally accepted hypothesis is that two or three million years ago, a storm carried several giant tortoises from mainland South America westward. Because they do not swim, turtles have only reproduced on their own islands, resulting in a distinct evolution that includes a phenomenon called insular gigantism. Today, there are 14 different species of Galapagos giant tortoises, all descended from a single ancestor.
Turtle populations have been decimated by seafarers
All 14 species are listed on the IUCN Red List as vulnerable or endangered.
Turtle populations were decimated by seafarers who hunted them for food after they discovered they could keep turtles alive on their ships with minimal effort, as the reptiles could survive on little food or water. “They were a great source of fresh meat for sailors, but that meant many of the species were heavily hunted,” Gaughran said. “And because they’re so long-lived, it’s hard for populations to recover.”
Fernanda is now at the Galápagos National Park Tortoise Center, a rescue and breeding facility where experts are doing everything they can to protect the turtles.