@beckygardener ...........
I've actually done something very similar, but kind of by accident.
I had a plant stand that I wasn't using, and a large plastic saucer that I was just storing. I put a couple of rocks inside instead of bricks.
I had to move it away from where I could see the birds using it because jays noticed the dry cat food I was leaving out for Scamp and decided that it was for them and not for my cat.
Once I moved my birdbath, the birds were in another part of the garden and left Scamp's food alone.
I like the idea of using the tomato cages. It frees up the plant stand again.
Smiles,
Lyn