It shows how much these animals don't want to be locked up, and how inherently barbaric zoos are.
I went to a chimpanzee sanctuary in South Africa a few weeks ago and was very impressed with how it was run. It rescues chimps who have been maltreated (in circuses, or kept as "pets" until the owners realise how strong and dangerous they are to humans) and who would die if they were released into the wild. They were very well organised and caring and I was struck by how dismissive they were of the way chimps are handled in many zoos. In fact had then even taken some in when the keepers were unable to handle them.
Sure this isn't part of the wall being erected for the EU's mandatory hard border?