Taco cook prepared bird (8)
I believe the answer is:
cockatoo
'bird' is the definition.
(cockatoo is a kind of bird)
'taco cook prepared' is the wordplay.
'prepared' indicates an anagram.
'taco'+'cook'='tacocook'
'tacocook' with letters rearranged gives 'COCKATOO'.
(Other definitions for cockatoo that I've seen before include "Lightly coloured crested parrot" , "Bird, a type of parrot" , "Australasian parrot" , "Crested bird" , "Illegal Aussie look-out man" .)