The Jackdaws are stil hacking away at stage 4 (deposit items left near the vending machine). Increased neighbor-cat traffic has led to fewer bird visits, but they still show up to deposit something 5-10 times a day. I don't want to keep the cats out - I like them too - but I do think I woud get more activity without them.

One thing that has become apparent is that the further above the ground that you mount the machine, the less likely the birds are to gather things from the ground to deposit. My platform is less than a meter above the balcony floor, but on the first floor (second floor in the US). Birds will take things from around the balcony to deposit, but have not brought in any of the marked bottlecaps I left in the garden below. I think that putting it at ground level in the open would facilitate making it to stage 5, but I don't have a place to do this yet.

If I moved to a place with a ground floor garden that would be ideal.