Bird heading away from its last animal sanctuary (7)
I believe the answer is:
titlark
'bird' is the definition.
(titlark is a kind of bird)
'animal sanctuary' is the wordplay.
'animal' becomes 'tit' (tit is a kind of animal).
'sanctuary' becomes 'lark' (I can't justify this - if you can you should believe this answer much more).
'tit'+'lark'='TITLARK'
'heading away from its last' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for titlark that I've seen before include "songbird" , "Magic lamp possessor" , "One flying" , "bird" , "Meadow pipit" .)