Bird getting leg up in South East (5)
I believe the answer is:
snipe
'bird' is the definition.
(snipe is a kind of bird)
'leg up in south east' is the wordplay.
'leg' becomes 'pin' (pin is a kind of leg**).
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'in' means one lot of letters goes inside another.
'south east' becomes 'se'.
'pin' in reverse letter order is 'nip'.
'nip' going within 'se' is 'SNIPE'.
'getting' acts as a link.
(Other definitions for snipe that I've seen before include "Pines like wading bird" , "Shoot from place of concealment" , "Game bird" , "river bird" , "Wading bird; shoot from concealment" .)