Perhaps I'm a southern bird (5,6)
I believe the answer is:
house martin
'bird' is the definition.
(house martin is a kind of bird)
'perhaps i'm a southern' is the wordplay.
'perhaps' indicates an anagram.
'im'+'a'+'southern'='imasouthern'
'imasouthern' is an anagram of 'HOUSE MARTIN'.
(Other definitions for house martin that I've seen before include "Remain south (anag) -- migratory bird" , "Bird of the swallow family" , "One having a flutter" , "Black-and-white bird" , "Eaves-mud-nest builder" .)