Extinct? No, this rare Galapagos giant tortoise is still around after all
A 50-year-old female fantastic giant tortoise turns out to be the same species as another found in 1906
Researchers have confirmed that a giant tortoise found on Fernandina Island in the Galapagos archipelago is one of a species that was thought to have gone extinct last century.
The female Fernandina Island tortoise, also known as the fantastic giant tortoise, was found on the volcanic island in 2019 by Galapagos National Park rangers and a TV crew on the hunt for supposedly extinct species.
"It was such a shock. There had been rumours over the decades that perhaps there were still some tortoises on Fernandina Island, but there was sort of tenuous evidence at best," Evelyn Jensen, a lecturer in molecular ecology at Newcastle University, told As It Happens guest host Catherine Cullen.
"Maybe there was evidence of tortoises trampling some vegetation, but nothing concrete."
Jensen is part of the international research team that sequenced the tortoise's genome, and the lead author of the study on their findings published in the journal Communications Biology.
Their sequencing revealed that Fernanda is linked to a male tortoise found on the island in 1906, and that the two tortoises are distinct from all others in the Galapagos.
The delay in confirming that the turtles were linked was due in part to COVID-19, said Jensen. It took time to get permits to ship the turtle blood out of the Galapagos, and then labs were backed up because of the pandemic.
"That was just an agonizing wait," said Jensen.
Over a year after Fernanda was found, her blood was finally analyzed.
Fernanda is estimated to be over 50 years old, but is small for her size, according to Jensen. A full grown female tortoise usually has a carapace to about a metre in length, but Fernanda is closer to half a metre in length.
"Her growth was probably stunted because she was in a very small patch of habitat, so she didn't have access to a lot of resources and all the paths out of that particular area were blocked by flows of lava. And so she couldn't escape to find greener pastures," said Jensen.
If she is only 50 years old, she probably has at least a good 'nother 100 years to enjoy her life of luxury and captivity.- Evelyn Jensen, lecturer at Newcastle University
The fact that the island is an active volcano may hold the key to the small number of tortoises found there.
Jensen said that at one time there were more giant tortoises on the island for the species to have evolved to be distinct from other Galapagos tortoises but volcanic eruptions over the past decades, or even centuries, have destroyed parts of the habitat, leading to smaller patches of liveable space on the island.
Shell shape gives turtle its name
The fantastic giant tortoises are named for the shape of their shells, said Jensen.
"The Galapagos tortoises come in sort of two general morphologies. There [are] the dome shaped tortoises which look kind of a standard tortoise, like an upside down bowl," she said.
"Then there are species that have what's called the saddleback shell shape. And so they have [an] upward arch at the front end of their shell. And this gives them a much greater range of motion with their necks."
The tortoise now lives in captivity in the Galapagos National Park Breeding Center. Jensen herself hasn't met the turtle yet, but has a visit planned for September.
Since Fernanda was found, there have been two more expeditions to the island to try to determine if there are other tortoises living there.
Jensen said there is some evidence of several other tortoises on the island, such as tracks, scat and crumpled vegetation but they aren't "concrete" proof, and more expeditions are planned for the future.
"It's just really difficult terrain to cover, to work through, to search for these tortoises. And so it's not an easy task," she said.
If no other tortoises are found, that will make Fernanda an endling, or the last of her species.
"But if she is only 50 years old, she probably has at least a good 'nother 100 years to enjoy her life of luxury and captivity," said Jensen.
Written by Andrea Bellemare. Produced by Kate McGillivray.