Transported bird of prey — no alternative (4)
I believe the answer is:
rapt
'transported' is the definition.
(both can mean enchanted or fascinated)
'bird of prey no alternative' is the wordplay.
'bird of prey' becomes 'raptor' (raptor can mean a bird of prey).
'no' suggests deleting specific letters.
'alternative' becomes 'or'.
'raptor' with 'or' taken away is 'RAPT'.
(Other definitions for rapt that I've seen before include "Ecstatic - engrossed" , "Ecstatic in part" , "Held spellbound" , "Enthralled, captivated" , "Part being transported" .)