Am into brief period of wild behaviour before starting on studying birds (9)

'am into brief period of wild behaviour' is the definition.
I can't tell whether this definition defines the answer.

'before starting on studying birds' is the wordplay.
'before' means one lot of letters go next to another.
'starting' suggests taking the first letters.
'birds' becomes 'flaming' (I can't explain this - if you can you should give a lot more credence to this answer).
The first letters of 'on studying' is 'os'.
'os' put after 'flaming' is 'FLAMINGOS'.

Can you help me to learn more?