For the first time in a century, babies of the endangered Pinzon giant tortoise have been born in the wild in the Galapagos islands, scientists said.
An expedition in 1970 found only 19 adult tortoises on the archipelago's Pinzon island, averaging 70 years old, so scientists removed them to start a captive breeding programme on Santa Cruz island.
The scheme produced juvenile tortoises that were transplanted back to the species' home island.
Danny Rueda, who is in charge of conservation and restoration of ecosystems in the Galapagos, said that in December six infant Pinzons were found to have been born on the island.
He said there are now 650 juvenile and adult tortoises on Pinzon.
Mr Rueda said the reintroduction of the tortoise was helped by the 2012 campaign to eradicate rats that infested Pinzon and other islands in the archipelago after being introduced long ago by passing ships. The rats prevented the reproduction by tortoises and other species.
"Finding the six baby tortoises tells us that the process of eradicating rats succeeded," he said.
"We have begun to see that the ecosystem has begun to restore itself" on Pinzon, Mr Rueda added. "It is a process that takes a long time. But the first step is the birth of tortoises in their natural habitat, which a century ago did not happen."
The Galapagos, an Ecuadorean territory in the Pacific about 620 miles (1,000 kilometres) from the mainland, was declared a World Heritage Site by Unesco in 1978 because of its unique land and marine animals and vegetation. That flora and fauna helped inspire Charles Darwin's theory of evolution.