Separate escarpment for bird (9)
I believe the answer is:
partridge
'bird' is the definition.
(partridge is a kind of bird)
'separate escarpment' is the wordplay.
'separate' becomes 'part' (both can mean to split or break apart).
'escarpment' becomes 'ridge' (I've seen this before).
'part'+'ridge'='PARTRIDGE'
'for' is the link.
(Other definitions for partridge that I've seen before include "Flier" , "Flighty type" , "Animal" , "early Christmas present" , "Game bird (in a pear tree?)" .)