Hare about like a bird (4)
I believe the answer is:
rhea
'bird' is the definition.
(rhea is a kind of bird)
'hare about' is the wordplay.
'about' indicates anagramming the letters.
'hare' is an anagram of 'RHEA'.
'like a' acts as a link.
(Other definitions for rhea that I've seen before include "Flightless bird from South America" , "Small 'ostrich'" , "Flightless bird -- satellite of Saturn" , "Titaness" , "Grounded bird" .)