 Over the next 50 years, this program resulted in major successes in the recovery of giant tortoise populations throughout the archipelago.In 1965, the first tortoise eggs collected from natural nests on Pinzón Island were brought to the Charles Darwin Research Station, where they would complete the period of incubation and then hatch, becoming the first young tortoises to be reared in captivity.The introduction of black rats onto Pinzón sometime in the latter half of the 19th century had resulted in the complete eradication of all young tortoises.