人口不足
Population decline accelerated with the early settlement of the islands in the early 19th century, leading to unregulated hunting for meat, habitat clearance for agriculture, and the introduction of alien mammal species. Feral pigs, dogs, cats, and black rats have become predators of eggs and young tortoises, whilst goats, donkeys, and cattle compete for grazing and trample nest sites. The extinction of the Floreana species in the mid-19th century has been attributed to the combined pressures of hunting for the penal colony on the relatively small island, the conversion of the grazing highlands into land for farming and fruit plantations, and the introduction of feral mammals.