Birds coming in to feather nest (5)
I believe the answer is:
ernes
'birds' is the definition.
(erne is a kind of bird)
'coming in to feather nest' is the wordplay.
'coming in' says the answer is hidden in the clue.
'ERNES' is hidden within 'to feather nest'.
(Other definitions for ernes that I've seen before include "Certain birds" , "Irish lough's" , "They fly across the sea" , "Sea-eagles" , "sea eagles" .)