I am sitting outside at present watching the darkness yb s exercise ,I have just started working them hard the last few nights they are starting to range and gain height with that comes the falcon problem ,She went at them last night singling one out but missing it the rest just kept exercising she came back at them at a greater height but after a while of tracking them flew away ,she has been at them 10minutes ago but failed again 35 or so are at a height still flying an hour after I let them out they will not be so lucky every night but if they don't get put up and fit they have no chance, When I lived on the outskirts of the town 23years ago when the falcon attacked them then they would immediately hit the ground and fly into things they see them every day here so seem to accept it I have the other alternative give them up but I ain't doing that ,Good luck .