so whats yr point fkm? are those "professional research" case u read apply to here? if not why u raise it here?
although bird ringing is a well known activites to most HKBWS members but seems some newbie like u not so sure what it is and dunno who is the host of this activities which held every weekend in the very early morning in Mai Po by some HKBWS volunteer for many years.
try to wake up early on Sat and go Mai Po Education centre before sun riase, spent some times with the profesional there like our Chiarman HF Chueng or if you see nobody there you may still read the poster on the small hut next to the EC and I think should enough to make you understand more .
lets back to the Flycatcher, u got any idea which species it is?
OC