 Like many animals that evolved in isolation from significant predators, the dodo was entirely fearless of humans.This fearlessness and its inability to fly made the dodo easy prey for sailors.The human population on Mauritius (an area of ) never exceeded 50 people in the 17th century, but they introduced other animals, including dogs, pigs, cats, rats, and crab-eating macaques, which plundered dodo nests and competed for the limited food resources.