Anything from blowing his ears out with calling to silence. If he hangs up I'll usually start with the silent treatment to see if that troubles him and peaks his interest. If he has already proven himself to be really reserved, I likely will not drastically pick up the calling. I have, however, tried to turn them inside out with calling and had that work as well. Its all about trying to read the bird..........and I won't ever claim to be an expert at that.