Bird's audibly wavering cry (5,3)
I believe the answer is:
tawny owl
'bird's' is the definition.
(tawny owl is a kind of bird)
'audibly wavering cry' is the wordplay.
'audibly' shows a homophone (sound like).
'wavering' becomes 'torn' (both can mean indecisive).
'cry' becomes 'yowl' (yowl is a kind of cry**).
'torn' is a homophone of 'tawn'.
'tawn'+'yowl'='TAWNY OWL'
(Other definitions for tawny owl that I've seen before include "Bird of prey, Strix aluco" , "Common hooting bird" , "hooter" , "Deputy Brownie guider" .)