Vigil after cat caught bird (9)
I believe the answer is:
kittiwake
'bird' is the definition.
(kittiwake is a kind of bird)
'vigil after cat caught' is the wordplay.
'vigil' becomes 'wake' (wake is a kind of vigil).
'after' is a charade indicator (letters next to each other).
'cat' becomes 'kitty' (informal term for a cat).
'caught' shows a homophone (sound like) (to catch something can mean to hear it).
'kitty' is a homophone of 'kitti'.
'wake' put after 'kitti' is 'KITTIWAKE'.
(Other definitions for kittiwake that I've seen before include "Bird" , "Arctic gull with yellow bill and black legs" , "Small pearl-grey gull" , "Oceanic gull" , "A seagull" .)