Meet Diego, a 130-year-old giant tortoise, who may have single-handedly saved his entire species from going extinct. Diego is believed to have fathered 40% of the population of giant tortoises on the island of Española in the Galápagos, according to CNN. When Diego arrived at the San Diego Zoo's captive breeding program, there were just two males and 12 females, but largely thanks to his libido, the population is now over 2,000. In the 1960s, Diego was selected to join San Diego Zoo's program along with 13 other tortoises, but none of them contributed as much as Diego."He's contributed a large percentage to the lineage that we are returning to Española," Jorge Carrion, the park's director, told AFP news agency. "There's a feeling of happiness to have the possibility of returning that tortoise to his natural state."Thanks to Diego, the program was a true success and allowed the Española island to recover its habitat conditions and of the tortoise population.Now, Diego is in quarantine before his well-deserved return into the wild to his native Española Island in March, after several decades spent living in San Diego Zoo.