As soon as it was apparent that he was studying the photos and wanted more, people began lining up behind me, crowding in, making inane comments like, "wow, he's really intelligent". Of course, he's really intelligent! And bored, and in jail. I know they are well cared for, I know that they are endangered, and his life serves a purpose educating. Tell him that.
I don't get there as much as I'd like, but the next time I go, my iPad will be loaded with more photos of his kind, of foods he might like, perhaps some animals. I am interested to see what he's looking for, what he wants to see, and perhaps to see if I can give something back rather than just staring.