He/she's been hanging around our place for about a week now (near Tarves, Aberdeenshire).  Seems quite content.  Not exactly tame, but certainly not wild.  I don't know the first thing about homing pigeons, but thought this might be one because of the rings and colouring.  I haven't been able to contain it, or get a good look at the rings (otherwise I would have made a proper stray report).  All I know is what's in these photos (follow link to album):   http://imgur.com/a/orakZ   I don't fancy anyone's chances of catching it.  Seems far too flighty.  But you might have tricks I don't know about