Extinct New Zealand bird (3)
I believe the answer is:
moa
'extinct new zealand bird' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for moa that I've seen before include "Extinct flightless NZ_bird" , "Gigantic extinct bird" , "Bird no longer" , "Early bird" , "bird that became extinct" .)