Birds caught with trouble are located among larks (13)
I believe the answer is:
capercaillies
'birds' is the definition.
(capercaillie is a kind of bird)
'with trouble are located among larks' is the wordplay.
'with' is an insertion indicator.
'trouble' becomes 'ail' (synonyms).
'are located' becomes 'clie' (I can't explain this - if you can you should believe this answer much more).
'among' is an insertion indicator (inserted letters are placed among others).
'larks' becomes 'capers' (lark can mean a caper or bit of fun).
'ail' put into 'clie' is 'caillie'.
'caillie' going within 'capers' is 'CAPERCAILLIES'.
'caught' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Another definition for capercaillies that I've seen is " Grouse".)