Persevere to maintain a bird as pet (4,2,2)
I believe the answer is:
keep at it
'persevere' is the definition.
(to keep at something is to persevere with it)
'maintain a bird as pet' is the wordplay.
I cannot really understand how this works, but
'maintain' could be 'keep' (synonyms) and 'keep' is located in the answer.
'a' is found in the answer.
'bird' could be 'tit' (tit is a kind of bird) and 'tit' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'to' acts as a link.
Can you help me to learn more?
(Other definitions for keep at it that I've seen before include "carry on" , "Persevere" , "Continue" .)