Possible Clues:

• Flightless bird that runs the airline in Animal Crossing
• Bird on Mauritius, once
• Extinct bird with a silly name
• Bird that had a repeating sound?
• Double act that's no longer with us
• Mauritius bird of old
• Nitwit of an extinct bird?
• Old-fashioned person repeating the same thing again
• Bird that had no natural predators until humans arrived
• Bird with a reduplicative name