Diego the tortoise, saviour of his species, will soon return to his home in the Galapagos islands nearly 80 years after being taken from it. As part of a conservation program, he has sired hundreds of teeny tortoises, helping to bring the population up from a mere handful of reptiles to around 2,000 over the past few decades.
Diego is a native of Española Island and is known as an Española giant tortoise (Chelonoidis hoodensis). Almost eight decades ago, he was plucked from the island by a scientific expedition and taken to San Diego Zoo in California. But in the 1960s, a breeding program was set up to try to save his dwindling species – there were just 12 females and two males alive on Española in 1970, and they were too spread out across the island to breed with each other.
Diego was brought to Santa Cruz Island in the Galapagos to join the program, along with 14 fellow Española tortoises. Together, they produced hundreds of baby tortoises that were released back onto their native island. Now, Española’s population stands at about 2,000 giant tortoises, and Diego played a big role in that repopulation.
It seems Diego is a particularly virile reptile, fathering far more babies than his fellow captive breeders. A family tortoise, he's fathered 800 offspring and is believed to be the patriarch of about 40 percent of the tortoises on Española today.
"About 1,800 tortoises have been returned to Española and now with natural reproduction we have approximately 2,000 tortoises," Jorge Carrion, director of the Galapagos National Parks service, told AFP. "This shows that they are able to grow, they are able to reproduce, they are able to develop."
As with the plight of many animals around the world, the decline of the Española tortoise and its relatives on other Galapagos islands has mainly been due to humans. Long ago, whalers, sailors, and pirates killed around 100,000 of the particularly “tasty” animals, finding them to be a handy food source as they could be loaded onto ships and survive for a long time without food or water. Humans have also introduced alien species to their islands, such as rats, pigs, and cats, which steal their precious eggs and compete with them for food.
We have already lost some species of Galapagos tortoise and cannot afford to lose anymore. In 2012, Lonesome George, the last known Pinta Island tortoise died. He was believed to have been about 102 years old. The Galapagos archipelago needs its gentle giants because they play an important role in controlling and dispersing the islands’ plants. As they eat plants, trample on them, and disperse seeds, giant tortoises are known as a keystone species as they have a disproportionately large effect on their surrounding environment compared to other animals.
At the ripe old age of 100, Diego will finally return to his home island in March, eight decades after he was pinched from it. He will live out the rest of his days with his many relatives, munching on delicious plants in peace.
"He's contributed a large percentage to the lineage that we are returning to Española," Carrion told AFP. "There's a feeling of happiness to have the possibility of returning that tortoise to his natural state."