I also tried a new treat - mealworms! I read a study that said coturnix used in operant conditioning studies worked harder and longer for mealworms with less fasting, so I thought I would give them a try. They're a huge hit! Brita's getting good at getting several in one peck, though, so I have to be fast.
I am working on making the green square 3D and gradually increasing the height of it until I can get her to hop onto a little pedestal when the green square is on it.