The birds always place them before us (4)
I believe the answer is:
emus
'the birds' is the definition.
(emu is a kind of bird)
'them before us' is the wordplay.
'them' becomes 'em' (abbreviation).
'before' is a charade indicator (letters next to each other).
'em'+'us'='EMUS'
'always place' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for emus that I've seen before include "Running birds" , "Large flightless birds of Australia" , "Aussie birds" , "Largest native Australian birds" , "laboratory units" .)