Bird wasn’t emu, unfortunately (4,4)
I believe the answer is:
mute swan
'bird' is the definition.
(mute swan is a kind of bird)
'wasn't emu unfortunately' is the wordplay.
'unfortunately' indicates an anagram (a bad or unfortunate spelling).
'wasnt'+'emu'='wasntemu'
'wasntemu' with letters rearranged gives 'MUTE SWAN'.
(Other definitions for mute swan that I've seen before include "creature" , "Common waterbird" .)