Avian perch (5)
I believe the answer is:
roost
'avian perch' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for roost that I've seen before include "Perch where bird sleeps" , "Place on which bird rests" , "Place where birds perch or settle for sleep" , "Fowl's perch" , "Settle down (on a branch?)" .)