Lusty creature in a Roman street for local birds (8)
I believe the answer is:
avifauna
'local birds' is the definition.
(avifauna are the birds of a local region)
'lusty creature in a roman street' is the wordplay.
'lusty creature' becomes 'faun' (lusty spirit in Greek myth).
'in' is an insertion indicator.
'roman street' becomes 'via' (Italian word for a street).
'a'+'via'='avia'
'faun' going within 'avia' is 'AVIFAUNA'.
'for' is the link.
(Other definitions for avifauna that I've seen before include "Flyers locally" , "Local birds" , "Bird collection" , "The birds of a particular region" .)