Pay lots of attention to him when you see him doing it to encourage the behavior, and if you have a treat handy you can give him that too right after he finishes. Here's my article on clicker training which can help you work toward getting him to do it on command:
http://www.littlefeatheredbuddies.com/i ... icker.htmlHere's an excellent book on clicker training for birds:
http://smile.amazon.com/Getting-Started ... 890948152/ The author has a yahoo group at
https://groups.yahoo.com/neo/groups/Bird-Click/info and you don't have to buy the book to belong.
Edit: maybe the author isn't actually on that group any more since I looked just now and don't see her posting in the last few months. But there's another highly skilled bird trainer giving advice.