The swine put Birkenhead right on the map! (5)
I believe the answer is:
beast
'the swine' is the definition.
(I've seen this in another clue)
'birkenhead right on the map' is the wordplay.
'birkenhead' becomes 'b' (head letter of 'birken').
'right on the map' becomes 'east' (I've seen this in another clue).
'b'+'east'='BEAST'
'put' is the link.
(Other definitions for beast that I've seen before include "Dangerous animal" , "Nasty type" , "Inhuman person" , "horse?" , "rotter" .)