I had a pigeon reported from within an army barracks once. Arranged with Amtrak to pick up the pigeon from there. The pigeon was left at the front gates awaiting pick up. Amtrak failed to pick up the pigeon, their excuse...........................they knocked but nobody answered.
Think there's many reasons, one not mentioned yet is racing y/birds on systems. Inexperienced y/birds are sent on eggs, w/hood or being split all week and allowed to run together on Fridays. They just get over excited and cant handle it early doors.
I wouldn't go to every Tom, Dick and Harry for pigeons.
I would study the results in the fancy press, not the adverts.
Buy from one source to cut down the chances of inheriting health problems into your loft.
Dont know about squirels Samantha but could be magpies/crows if they can find a way into your lofts. Funny was only talking about this last night............the culprit was a crow.
Think it depends on what type of races you want to win that will dictate as to what system you fly, it does around here anyway. I fly North Rd and 90% of our racing is up to 300mile. We fly sprint type pigeons and the w/hood & roundabout method is favoured by most. I do keep 6 pair of naturals for the longer couple of races we have though. To be honest I quite enjoy racing the naturals more so than the w/hood team but they cant live with the w'hoods up to 300mile. Horses for courses I think.