Swagger like a blackbird (4)
I believe the answer is:
crow
I believe this clue is a double definition.
'swagger' is the first definition.
(thesaurus)
'a blackbird' is the second definition.
(crow blackbird is a kind of blackbird)
'like' acts as a link.
(Other definitions for crow that I've seen before include "Large black bird" , "Make sound of cock - bird" , "Bird - birdcall" , "Native American -- bird" , "Bird in 1's poems" .)