Badger returned to capture seabird (6)
I believe the answer is:
gannet
'seabird' is the definition.
(type of seabird)
'badger returned to capture' is the wordplay.
'badger' becomes 'nag' (both can mean to annoy or complain at).
'returned' says the letters should be written in reverse.
'to capture' becomes 'net' (both can mean to trap).
'nag' written backwards gives 'gan'.
'gan'+'net'='GANNET'
(Other definitions for gannet that I've seen before include "Marine bird - greedy person" , "flyer" , "Ten nag the sea-baird" , "Large seabird, white with dark markings" , "Voracious bird" .)