Destroy cave to get bird (6)
I believe the answer is:
avocet
'bird' is the definition.
(avocet is a kind of bird)
'destroy cave to' is the wordplay.
'destroy' indicates an anagram (I've seen this in other clues).
'cave'+'to'='caveto'
'caveto' with letters rearranged gives 'AVOCET'.
'get' is the link.
(Other definitions for avocet that I've seen before include "Long-legged wader" , "RSPB emblem" , "Long-legged wading bird with upward-curving bill" , "Black and white Eurasian long-legged wading bird" , "Curved-bill shore bird" .)