Commotion behind boundary where birds may be sheltering (8)
I believe the answer is:
hedgerow
'where birds may be sheltering' is the definition.
(birds might nest in a hedge)
'commotion behind boundary' is the wordplay.
'commotion' becomes 'row' (a row is an argument or commotion).
'behind' is a charade indicator (letters next to each other).
'boundary' becomes 'hedge' (I've seen this before).
'row' put after 'hedge' is 'HEDGEROW'.
(Other definitions for hedgerow that I've seen before include "Field boundary" , "Line of shrubs as barrier" , "Field border" , "Bushy boundary" , "natural fence" .)