Alejandra Martins
BBC News World
May 26, 2021
Scientists nicknamed her “Fernanda” and her find represents the best hope of saving her species from extinction.
The management of the Galapagos National Park (PNG) announced the discovery on Fernandina Island of a giant tortoise whose species was believed to be extinct more than a century ago.
The giant tortoise was found in 2019 on a joint expedition by the Galapagos National Park Directorate and the United States-based Galapagos Conservancy.
Genetic analyzes carried out at Yale University in the United States now confirmed that the solitary female tortoise is genetically similar to the so-called Fernandina Giant Tortoise (Chelonoidis phantasticus), a species of which no individuals have been reported for more than 100 years.
The find offers the possibility of restoring the turtle colony on Fernandina Island. And the great priority for scientists is to find other specimens on that same island to start a captive breeding program as soon as possible.
“We desperately want to avoid the same tragic end of Solitario Jorge, or Lonesome George” Danny Rueda, director of the Galapagos National Park, told reporters.
The famous tortoise known as Solitario Jorge became an emblematic species of the Galapagos Islands. Lonesome Gerge had been found in 1971 on Pinta Island. Efforts to mate with females of another genetically similar species were unsuccessful, and the tortoise was the last known specimen of its species Chelonoidis abingdoni.
Scientists hope to prevent something similar from happening with Fernanda.
“My team and Galapagos Conservancy planned a series of expeditions to Isla Fernandina in the second half of this year looking for other turtles,” Rueda said.
Genetic confirmation
Scientists believed from the beginning that the tortoise found in 2019 was a specimen of the missing Fernandina Giant Tortoise.
To verify their suspicions, blood samples from the turtle had to be analyzed by Yale University geneticist Gisella Caccone and her colleagues.
The scientist determined a close relationship between the DNA of the new specimen and that of a male Giant Tortoise native to Fernandina found in 1906 on an expedition of the California Academy of Sciences.
“100 years, maybe”
The turtle found in 2019 was transferred to the Giant Tortoise Breeding Center, which the PNG manages on Santa Cruz Island, in the center of the archipelago.
Washington Tapia, conservation director for the Galapagos Conservancy, noted that the turtle was underweight when found in its habitat, but has already gained weight and is in good health.
Tapia is one of the directors of the Giant Tortoise Restoration Initiative, in which his organization collaborates with Yale University.
The expert explained that Fernanda is 60, 80 or “100 years old, maybe”, since it is very difficult to calculate the age of a chelonian .
“Turtles are very long-lived animals and develop their sexual maturity very late (20-25 years). As the years go by they lose the concentric rings in their plates (in the shell) and when they reach 30-40 years they begin to Losing those rings in some cases faster and in others slower, but all end up with completely smooth plates after approximately 60 years, with which from that age it is impossible to know how old they are,” Tapia explained to BBC Mundo .
The turtle “measures only 54 centimeters in the carapace, which is a small size, compared to the largest ones that can measure more than 1.5 meters in length.”
The shape of the carapace is different from other species and very similar to the male found in 1906.
“Like looking for a needle in a haystack”
“One of the greatest Galapagos mysteries has been the Fernandina Island giant tortoise. The rediscovery of this lost species may have occurred just in time to save it,” said James Gibbs, vice president of science and conservation for the Galapagos Conservancy and professor of biology and conservation at the State University of New York.
“The first giant tortoise was discovered in 1906. But another individual was never seen again. And no one has been able to do a complete exploration of the island because it is so remote and the terrain is so difficult,” Gibbs explained to BBC Mundo.
“Although what looked like turtle tracks had been observed over the decades. So it is a great mystery whether or not a unique species of turtle existed at this remote volcano.”
“Now we urgently need to complete the search to find other turtles,” he added.
Finding partners for Fernanda will not be easy.
“The island is vast and it is almost impossible to walk around because of the rough lava. There are also eruptions. So there are probably few turtles present and finding and moving them from there even with a helicopter is very difficult,” Gibbs said.
Tapia explained to BBC Mundo that “the entire island is an active volcano and is one of the few volcanoes in which despite having installed two monitoring networks for volcanic activity, there is no seismic activity for several days or weeks before, but only 2 or 3 hours before, which makes it a high-risk place. “
“At least 60% of the island’s surface is covered with very rough lava flows that in a maximum of 3-4 hours finish the sole of a pair of boots, the angle of its slopes is very steep and there are a lot of hidden cracks in the vegetation,” added the expert.
“Furthermore, due to the absence of the main herbivore (the turtles), the vegetation is very compact and therefore very difficult for humans to walk. It is also an island of more than 600 km2, which is like looking for a needle in a haystack “.
If a male is found, he will be transferred like Fernanda to the breeding center in Santa Cruz to start a captive breeding program.
The young would be released in the future in safe habitats on Fernandina Island.
Extraordinary diversity
The Galapagos Islands, located about 1,000 kilometers west of the continental coasts of Ecuador, were declared in 1978 as a Natural Heritage of Humanity by UNESCO, thanks to their rich terrestrial and marine biodiversity.
About 30% of plant species, 80% of land bird species and 97% of reptile species are found nowhere else on the planet, Gibbs said.
In the case of the iconic giant tortoises, which can live for more than 100 years, multiple species evolved in response to the particular conditions on the island where they live, resulting in great variety in terms of shell sizes and shapes.
Lonesome George, for example, had a saddle-like shell that allowed him to lift his neck to reach taller bush leaves for food.
“The islands are very different from an ecological point of view. Some islands are very hot and dry, others cool and humid. The types of shells and limbs change to allow the turtles to adapt to different conditions. There are turtles with dome-shaped shells that only eat green vegetation at ground level and do not need to have long necks,” Gibbs explained to BBC Mundo.
“‘Phantasticus’ or the fantastic tortoise was named for its extraordinary horseshoe-shaped carapace and long neck. But females do not usually have these characteristics, so they are not evident in Fernanda.”
“Ready for any sacrifice”
Despite their ability to adapt, the Galapagos giant tortoises were not prepared to face a new enemy – the human being.
The giant tortoise populations of the archipelago were devastated in the 19th century due to exploitation by whalers and buccaneers and the introduction of invasive species such as goats. However, in the case of the Fernandina Island Giant Tortoise, the extinction is believed to have been due to volcanic eruptions.
The current population of giant tortoises in the Galapagos Islands represents only between 10% and 15% of their historical numbers, estimated between 200,000 and 300,000 individuals.
Will it be possible to prevent Fernanda from having the same fate as Lonesome Jorge?
There are hopes. Conservation organizations made calls to raise funds for the new expeditions.
And droppings and other clues indicate that there are at least two other giant tortoises on Fernandina Island.
“No turtles have been recorded in over 100 years and the only one we have found so far is an old female, probably over 100 years old, so if we don’t find other individuals soon, or if she dies, the species will be extinct. as it happened with the case of Solitario Jorge,” reflected Tapia to BBC Mundo.
“For me this is a challenge similar to the need to get a cure for a family member with a terminal illness, so it means being willing to make any kind of sacrifice to avoid extinction.”
Read the full coverage from BBC News Mundo at https://www.bbc.com/mundo/noticias-57258965
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