 When it was discovered that the central , small island of Pinzón had only 100 – 200 very old adults and no young tortoises had survived into adulthood for perhaps more than 70 years , the resident scientists initiated what would eventually become the Giant Tortoise Breeding and Rearing Program . Over the next 50 years , this program resulted in major successes in the recovery of giant tortoise populations throughout the archipelago . 
