Touched a bird (6)
I believe the answer is:
cuckoo
I believe this clue is a double definition.
'touched' is the first definition.
(both can informally mean mad)
'a bird' is the second definition.
(cuckoo is a kind of bird)
(Other definitions for cuckoo that I've seen before include "Bird; sort of clock" , "Intruder bird in the nest" , "Bird that fosters out its eggs" , "Slightly crazy -- bird" , "Hourly you might hear this" .)