Diego the 100-year-old tortoise who saved his species returns to his homeland

Diego is credited with fathering 40 per cent of the giant Galápagos tortoise population

A giant Galápagos tortoise credited with saving his own species after fathering hundreds of offspring in a breeding programme has returned to his homeland.

Diego, along with 25 other male tortoises, was released back to his native Española, one of Ecuador's Galápagos islands, aged 100 on 15 June after retiring earlier this year.

He had been taken to Galapagos National Park in Santa Cruz island as part of a breeding programme that was launched during the 1960s in an attempt to save the region's tortoise species.

The successful programme produced more than 2,000 giant tortoises since it began, with the Diego laying claim to around 40 per cent of that total, park rangers said.

Before the programme began, there were only 15 Chelonoidis hoodensis in the region, according to Jorge Carrion, the Galapagos National Park director.

“We are closing an important chapter” in the management of the park, minister Paulo Proano wrote in a tweet on Tuesday.

The national park service believes Diego left the Galapagos Islands 80 years ago during a scientific expedition.

He was one of three male tortoises involved in the breeding scheme – which involved 12 females – after being recruited from the US zoo where he had been living for 30 years, Galapagos Conservancy previously said.

One hundred-year-old Diego and his fellow breeders had been put in quarantine before returning to the wild so that they didn't carry seeds from plants that are not native to Española.

“The island has sufficient conditions to maintain the tortoise population, which will continue to grow normally,” said Washington Tapia, the director of the Giant Tortoise Restoration Initiative earlier this year.

A species of giant tortoise that was believed extinct was discovered on another Galapagos island earlier this year, Ecuador's government said.

The Fernandina Island tortoise had previously only been seen once before at the start of the 20th century.