Our neighbors have a chain link run that was placed on top of an old building foundation, so that gives it a firm base. Even so, they have had skunks actually dig under the foundation and others that have tried. The chain link kept the larger varmints out, but wild birds like starlings and sparrows were getting in, so they later covered the chain link with chicken wire. That stopped most of the wild bird traffic, but the occasional starling will still get in.......then can't get out. Those generally end up dying from lead poisoning.
The interesting thing about the chicken wire is how many holes show up over time as predators attempt to fight their way in. Often enough to know chicken wire alone would never work to keep predators out.
I have a standard chain link fence in the back, and while it keeps the birds in and some predators like large dogs out, cats, possums, coons and probably larger canines like a fox or coyote can go under it so easily it seems like it is not even there. The cats go under it and never even slow down. So it needs an apron to shut down that traffic. Or use the posts to run a single hot wire on a stand off insulator along the bottom.