A recent DNA study confirms that Diego is a very prolific breeder.
Diego, a Galapagos tortoise (Chelonoidis hoodensis), has, with the help of several amorous females, brought his species back from the brink of extinction, thanks to his sexual prowess and penchant for mating. Researchers speculate that Diego was taken from Española Island in the Galapagos island chain sometime between 1900 and 1959 and ended up at the San Diego Zoo.
During the early 1960s, there were just two males and 12 female Chelonoidis hoodensis Galapagos tortoises left on the island. They appeared in dire straits as a species. So in 1976, Diego, who began life on Española , was sent back to be part of the captive breeding program on the island. That program was deemed successful in 2014. In his 40 years as part of the program, he has been very prolific in adding to the species. Scientists have estimated that Diego fathered around 800 offspring since he was sent back to Española , where an estimated 2,000 Galapagos tortoises can now be found.
“We did a genetic study and we discovered that he was the father of nearly 40 percent of the offspring released into the wild on Española ," Washington Tapia, a tortoise preservation specialist at Galapagos National Park, told AFP. “He's a very sexually active male," said Tapia.“He's contributed enormously to repopulating the island."
While Diego was successful in bringing Chelonoidis hoodensis back from the brink of extinction, one of Diego's cousin's, Lonesome George, a Chelonoidis nigra abingdoni from nearby Pinta Island was not successful in captive breeding efforts for his species. However, there is a sliver of hope, as scientists have discovered 17 hybrid tortoises that include C. nigra abingdoni DNA at Volcano Wolf on the northern tip of Isabela Island.