Bird nuts rely on banter (8)
I believe the answer is:
raillery
'banter' is the definition.
(I know that banter can be written as raillery)
'bird nuts rely on' is the wordplay.
'bird' becomes 'rail' (a wading bird).
'nuts' indicates anagramming the letters (nuts can mean crazy).
'on' indicates putting letters inside (as in clothing 'on' a person).
'rely' anagrammed gives 'lery'.
'rail' going inside 'lery' is 'RAILLERY'.
(Other definitions for raillery that I've seen before include "Satirical banter" , "Banter, back-chat" , "Light teasing repartee" , "Badinage" , "Playful satire" .)