To give us a better understanding of where they get to and perhaps eventually find out why its about time the unions set up some kind of database. All organisations submit details of liberations (number of birds, weather, wind speed & direction, time of lib, % of returns etc.) Strays that are reported could also be added giving us a better picture of how they possibly became so. Until something constructive is done I'm afraid its going to continue to be guesswork and speculation.