The Dodo bird lived on the Mascarene Islands which are about 550 miles east of Madagascar until they got extinct in the late 17th century. Mauritius, the largest of these islands, had no indigenous land mammals or amphibians which means the Dodo had no enemies.

This changed when Europeans arrived in the 16th century who began to grow sugar cane, cotton and tobacco on the island. They brought with them hogs, goats and dogs. The Dodo was an easy prey to men and to the predators. Also, their nests were exposed and the eggs were easy food, too.

The first Europeans arrived around 1598 and it took them only until 1755 to destroy the bird.

There are good web sites about the Dodo bird, if you want to know more, here is one of them:
dodo

The Dodo Bird was found on the island of Mauritius off the coast of Africa. In 1598 Portuguese explorers first saw it and because the bird had never seen humans before at was not afraid of them. This meant that it was easily caught and was apparently very tasty. By 1681 the Dodo was extinct, literally eaten to death by people and their pets (dogs, cats, etc.)

For more information, please read here