A year ago, my cat had broken her leg (two compound fractures) after she fell off the balcony (7 stories). Miraculously she survived and lived two months with a bandage. Me and my girlfriend were thrilled. We found out that most likely she fell off the balcony because of crow birds who always try to tease her and fly just near her to make her jump and then fall. This behaviour of these smart birds is known among people who I asked. Now my cat is three times as big as she was and relatively heavy and I do not think if she falls again she is going to survive.
I observed several times those crow birds flies around her and she is trying to catch them. I tried several things to stop her from going to the balcony edge (1 meter wall, and she climbs on the top of it). I tried to put some plants (e.g. mint) that might keep her away. I tried corporal punishment. I tried to make sounds that does not like. Mistakenly, I thought I stopped her from going there, until I discovered that she just stopped in front of me and she goes there every night when I go to bed. Last time I locked her up in one room with all her stuff all the night. I felt so guilty about it and I do not know what to do. I cannot close the balcony doors, it too warm year-round here. She loves to stay in the balcony, it's quite spacious (4*6 m) and it's the only outdoor place she gets to. I just do not want her to climb the balcony screen, and I cannot keep watching her 24/7.