I have GOT to get a video camera or whatever they are called these days. My neighbour has a small bird feeder which cannot be perched upon and eaten from by larger birds like pigeons. As well, he hung the feeder with a foot long piece of #10 insulated copper wire so it would swing freely, thus being even more unstable. I just saw a pigeon repeatedly do the following.

It grabbed a perch with it's talons and then grabbed a corner of the "eave". It flapped it's wings vigorously, forcing the feeder to spin a half dozen revolutions. It released and went to ground under the feeder. The feeder spun wildy, spewing feed to the pigeon and it's buddies.