Australian bird, a sort of teal, is mimic (7)
I believe the answer is:
emulate
'mimic' is the definition.
(I've seen this before)
'australian bird a sort of teal' is the wordplay.
'australian bird' becomes 'emu' (I've seen this before).
'a sort of' indicates an anagram.
'teal' is an anagram of 'late'.
'emu'+'late'='EMULATE'
'is' acts as a link.
(Other definitions for emulate that I've seen before include "Imitate - rival" , "ambitious veteran" , "Try to equal or excel" , "Ape" , "Try to do as well as, copy" .)