Extinct birds are species of birds that have gone extinct due to a variety of reasons, such as human activity, climate change, and natural disasters. The three extinct birds mentioned in the crossword solutions are the Dodo (6 letters), DODOS (5 letters), and Moas (4 letters). The Dodo was a flightless bird native to the island of Mauritius in the Indian Ocean, and it became extinct in the late 17th century due to hunting and habitat destruction. The DODOS were also flightless birds, but they were native to the island of Mauritius and Rodrigues in the Indian Ocean, and they became extinct in the late 17th century due to hunting and habitat destruction. The Moas were a family of large, flightless birds native to New Zealand, and they became extinct in the late 15th century due to hunting and habitat destruction.