The dodo was a large flightless pigeon on the island of Mauritius in the Indian Ocean.
It had few natural enemies. But in the 1500s, European sailors arrived and found that the dodo was easy to hunt. By about 1680, all the dodos had been killed.
Around the world, about 150 bird species have gone extinct since then. Some died out naturally, but most died out due to humans. Global warming is a big new problem. It creates drought conditions. Some scientists say that nearly all the prairie wetlands could dry up. Many ducks nest in these wetlands.
