I also wondered about the net. Never considered the ball idea, that's very interesting. One thing the video doesn't cover is potential other solutions there are

I also wondered about the net. Never considered the ball idea, that's very interesting. One thing the video doesn't cover is potential other solutions there are for protecting birds. Maybe they have just been doing it for such a long time that nobody thinks about alternative solutions, combined with the fact that they have already spent money into the bird hut and other equipment and further investments in alternatives would just not have a higher net present value.