Shore bird flying to cave (6)
I believe the answer is:
avocet
'shore bird' is the definition.
(avocet is a kind of shore bird)
'flying to cave' is the wordplay.
'flying' indicates anagramming the letters.
'to'+'cave'='tocave'
'tocave' with letters rearranged gives 'AVOCET'.
(Other definitions for avocet that I've seen before include "Black and white Eurasian long-legged wading bird" , "Wading bird - octave (anag)" , "Long-legged wading bird with upward-curving bill" , "Curved-bill shore bird" , "Long-legged shorebird with upward-curving bill" .)