better off wrapping the trunk with mesh wire then hook a transformer to it to zap them when they touch it.
they might still figure out to jump above it but then again they might not.
that's the best thing I can think of that would be affective and doesn't look like trash hanging from a tree.
short of setting up a shooting station and spending your afternoons popping the visitors as they arrive, animal thieves show up alive but leave dead in a 5 gln bucket
