Galapagos hosts nursery for new species of giant tortoise
One of three centers in archipelago’s national park
PUERTO AYORA: Crowded under a rock in the Galapagos archipelago, the baby tortoises wait for the sun to go down to leave their shelter. Nothing disturbs these eastern Santa Cruz tortoises (scientific name Chelondis donfaustoi), which were determined just two years ago to be a new species native to the Ecuadoran islands that inspired Charles Darwin. Kept safe on Santa Cruz island and raised in captivity, their nursery is one of three centers in the archipelago’s national park where 12 species of giant tortoises, unique in the world, are bred.
Stretching their necks and poking their heads out of tiny shells, they nibble on nutritious, starchy leaves of tropical plants brought in from the continent 1,000 kilometers away. Digestion plunges them into afternoon slumber. “We let them stay a little hungry. That way, when they return to the wild they go looking for their food,” the director of the national park, Walter Bustos, told AFP.
It’s not yet time to let the tortoises go free. For that, their shells have to be 23 to 25 centimeters (nine to 10 inches) long, meaning around four or five years of age. That’s an insignificant span for these reptiles that can live up to a century and a half, reaching up to two meters (over six feet) long and weighing up to 450 kilograms. The eggs hatched several months earlier in the center, with several broods. In all, the park now has 120 of the eastern Santa Cruz tortoises born in captivity, joining the better-known Galapagos giant tortoise (Chelonoidis nigra) on this string of volcanic islands in the Pacific.
Ancient genus Giant tortoises arrived in the Galapagos around three or four million years ago, and it appears ocean currents likely scattered them across the islands. They developed into 15 species, of which three are extinct, each adapting
Protective captivity ensures their survival
to its territory.
The tortoise population was decimated by pirates and whale-hunters who captured them for their meat, and who introduced invasive species such as dogs, goats and rats. The tortoises’ fat, transformed into oil, for a long time fueled street lamps in Ecuador’s capital Quito and the city of Guayaquil on the Pacific coast. “The tortoises are sorts of engineers in the ecosystem,” Washington Tapia, a biologist at the US-based Galapagos Conservancy, said. “Through their movements they shape their environment, creating spaces where other species can develop, and they are the best sowers of grain that exist.”
Tortoise patrols
Up until 2002, the scientific community believed all the tortoises on Santa Cruz island, the second biggest in the Galapagos, came from the same species, Chelonoidis porteri. But after years of genetic studies it was discovered in 2015 that those on the eastern part of the island, on Cerro Fatal (Deadly Hill), were a species apart: Chelonoidis donfaustoi. There are not many of them, fewer than 400, and the threat of predators prompted park authorities to collect their eggs to hatch them and raise the babies in protective captivity to ensure their survival.