Young, hooting bird (5)
I believe the answer is:
owlet
'young hooting bird' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for owlet that I've seen before include "Young bird; moth" , "Small bird of prey from Africa and Asia" , "Young nocturnal flier" , "Junior member of parliament" , "Offspring of the wise one?" .)