Beautiful pics! I work with some of the same birds at my zoo, just minus the hyacinth and golden conures. They probably rotate the one in the last pic.
We tend not to do that at our zoo (but we also don't have as many birds on perches!), but with our U2 we move him between 2 different perches. We're hoping to get a sign soon that tells people his name and tells them that if he's not at one perch, he's at another.