Hood's birds (6)
I believe the answer is:
robins
'hood's birds' is the definition.
'robins' can be an answer for 'birds' (robin is a kind of bird). I am not certain of the 'hood's' bit.
'hood's birds' is the wordplay.
'hood' becomes 'Robin' (Robin Hood).
'birds' becomes 's' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'robin'+'s'='ROBINS'
Can you help me to learn more?
(Other definitions for robins that I've seen before include "Birds with reddish breasts" , "Birds with red breasts" , "Friendly winter birds" , "Small songbirds" , "Small thrushes" .)