The term 'Large Extinct Bird' can be summarized by three crossword solutions: MOA (3 letters), DODO (4 letters), and GREAT AUK (8 letters). The MOA was a large, flightless bird native to New Zealand that became extinct in the late 19th century. The DODO was a large, flightless bird native to the island of Mauritius that became extinct in the 17th century. The GREAT AUK was a large, flightless bird native to the North Atlantic Ocean that became extinct in the mid-19th century. All three birds were hunted to extinction by humans.