Fifteen giant tortoises managed to save their species in captivity. Twelve male and three female of these tortoises from the Galapagos Islands, in Ecuador, were the last remaining of the Chelonoidis hoodensis species, on the verge of extinction several decades ago by the action of pirates.
The captive breeding program of the Galapagos National Park kept the 15 tortoises in captivity to increase the population of these turtles. Among them, a male giant tortoise named Diego stood out because he fertilized 40% of the hatchlings. Diego, who is now 100 years old, is the father of 800 tortoises born under this program.
So the Chelonoidis hoodensis species is now safe. Hence the management of the Galapagos National Park has closed the captive breeding program.
Diego and the other 14 tortoises will return to their original habitat on the Galapagos Island of Española as of March 2020. Diego has not lived there for almost eighty years, because he was moved to the San Diego Zoo in California in the 1930s.
When the captive breeding program began in the mid-1960s, the other 14 giant tortoises were taken from Española Island to Santa Cruz Island in the center of the archipelago. Diego was transferred to Santa Cruz from the San Diego Zoo in 1976.
The Giant Tortoise Restoration Initiative (GTRI), comprised of the Galapagos National Park management and the Galapagos Conservancy, found that the habitat on Española Island has already recovered its conditions thanks to the program, according to a statement from the Galapagos National Park management, so the tortoises will be able to return.
Director of the GTRI Washington Tapia said, quoted in the statement, that the last census in 2019 and all the data available since 1960, about the island and its population [including the recovered] turtles, are firm enough to to affirm that these conditions exist.
As part of the initiative, non-native species were also eradicated and cacti were regenerated through the Galapagos Green 2050 program. This, according to Carrión, has also helped “to ensure that the island’s ecosystems now have adequate conditions to support the growing population of turtles.”
They also developed, Tapia sapid, possible scenarios for the next 100 years that support these conclusions. “The turtle population will continue to grow normally, even without any new repatriation of juveniles,” he said.
Española Island is located in the southeast of the Galápagos archipelago, which has 13 large islands, six medium islands and 107 rocks and islets. Galápagos is a province of Ecuadorian territory and is located about 1,000 kilometers from its coast.
Española Island is easily accessible, Susana Madera writes in an EFE report. Carrión told her in an interview that in all of Galápagos only 15% of the original population of turtles remains: 400,000 individuals from 15 original species.
The national park’s director said that decades ago pirates and whalers took refuge in the archipelago and nearly wiped out the giant tortoises because they used them for food. “They fed themselves on the site and took the giant turtles on their boats, which could ‘survive up to a year, or even longer, without eating or drinking’, Madera wrote.
To date, 1,800 of the 2,000 giant tortoises living in Española Island were transferred there from the Santa Cruz breeding center, “with a survival rate of 52 percent,” according to the EFE report.
“By law, we need other specimens that do not come from Diego so that the genetic variability of the Española tortoises is healthy and can even be increased,” Carrión said.
The presence of turtles is fundamental to the survival of other Galapagos species like the albatross, because the turtles open up the spaces those birds need to take off or land.
“In the absence of the tortoises, the woody plants progress, invade quickly and leave no space for bird nesting,” Carrión explained to Madera.
The fertile Diego tortoise weighs 80 kilos and reaches 1.5 meters in height when he stretches his legs and neck, according to an Associated Press report.
Before their return to the Española Island in March 2020 (the date has not yet been specified), Diego and the other 14 tortoises Chelonoidis hoodensis species remain in quarantine, in order to prevent them from carrying seeds from plants they have eaten on Santa Cruz that are not native to the island to which they will return.