Dodo birds became extinct because of the combination of overhunting by humans and non-native predators that were introduced by humans to their native island. Dodo birds only inhabited the island of Mauritius, where they had no natural predators. Accordingly, the dodo bird had lost the power of flight and possessed few defensive behaviors by the time humans arrived on the island.
Dodo birds were eaten by Dutch settlers who colonized the island. Because the birds could not fly and were clumsy when walking, they were easy for the humans to catch. Even though the birds did not taste very good, the settlers hunted them ruthlessly, preserving those they could not eat immediately.
While this overhunting was an important factor in their extinction, it was nest-raiding predators, such as rats, cats and monkeys, that caused the most damage to the dodo. As dodo birds only produce one egg at a time, they could not cope with the intense pressure they faced in the introduced animals.
It only took about 75 years for humans and introduced animals to completely eradicate the strange birds. While no living person has ever seen a dodo bird alive, some scientists hope to produce living specimens by using DNA contained in the fossils, bones and feathers kept in museums.