Audubon subject (4)
I believe the answer is:
bird
'audubon subject' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bird that I've seen before include "chat, perhaps?" , "Creature - time in prison" , "Flying creature" , "Flier - spell in prison" , "Prison sentence - hawk, perhaps" .)