Rival bird is not on time (7)
I believe the answer is:
emulate
'rival' is the definition.
(I've seen this before)
'bird is not on time' is the wordplay.
'bird' becomes 'emu' (emu is a type of bird).
'is not on time' becomes 'late' (I've seen this in another clue).
'emu'+'late'='EMULATE'
(Other definitions for emulate that I've seen before include "Follow suit" , "Copy - rival" , "Contend with" , "Imitate, try to equal" , "Attempt to match" .)