Zoo to Santa Cruz Island, also in the Galapagos, to join a breeding program there about 50 years ago. The hefty hunk, along with another 14 other adults, together naturally reproduced an estimated 1,000 tortoises, with most being returned back to Espanola, according to AFP. After a rather busy half-century, Diego still won’t be retiring. At 100 years old and 175 pounds, he’ll return to his native Espanola after decades philandering abroad. “He’s contributed a large percentage to the lineage that we are returning to Espanola,” Jorge Carrion, the director of the Galapagos National Parks service, told the outlet. “There’s a feeling of happiness to have the possibility of returning that tortoise to his natural state,”.