Read this thread with great interest,can't come up with any answers only observations. When I first started with pigeons in the early sixties I had never heard of antibiotics or BOP as a problem,we never had a phone let alone a mobile and we trained our y/birds 45-90mls by rail before Dr. Beeching got to work.We always had birds missing on race days but most seemed to show the next day,1963 was a year when losses were very heavy and I reported missing birds all over the country and the best part of 50 years on we are still trying to work out the cause of these losses,hope someone sorts it out soon I haven't got another 50 years left.