Hi Raven! Welcome...glad you've dropped in and are going to try some totems. Be forewarned....they are terribly addicting! I took mine out to put in the garden the other day and I have about 20 or so and more to make.

I tend to decide what I want first by stacking the pieces up (very carefully or they will fall...my cat tends to love to "help" me with that part!) Then, I glue about 3 pieces together and let them dry at least 24 hours before I stack those pieces together for the final gluing. I've found that helps them not to slide around as much. I let mine cure at least a week before I put them out.

I do have some that have the plates right side up and they do catch the water. You will have to clean them as mine tend to get green with algae after a while, but since you're in a hotter, drier climate, you may not have as much of an issue with that. As for birdseed, you can use that, but you will have to replace it after a long rain. If it's just a shower, often it will dry out. Or you can drill some holes in the plates....regular pottery plates are easier to drill, but they are not necessary. Just remember to put something heavy and/or wider at the base for stability so they won't topple in the wind or when the birds land on them.

As for the caulking gun, you will learn to cut a smaller hole to help control the flow. At the end of caulking, I release the pressure on the gun and either put the cap on it or stick a nail in the end or you can even just put tape on the end, but the key is releasing the pressure by pulling the back handle back a little.

Good luck and I look forward to seeing your creations!

Thanks so much that was very helpful. I did cut a small hole, but I was not releasing the pressure!
I found several of the really heavy microwave platters which should make good heavy bases.
Appreciate your feedback.
I will definitely post pictures.