I think what Jerry was trying to convey here was a tool to use to show the different stress levels a bird can go through. I don't think he was saying that a bird has to have a "Perfect" home envioroment. If a bird was to have a "Perfect" home envioroment, it would be in the wild as nature intended. But since our birds are not in the wild, it is our responsibility to meet as many needs as possible to make their lives worthwhile and fulfilled. If that is 5,6,7,10 or 20, you do what you can do. From reading this message site, I feel Jerry thinks highly of you people who have taken in and rescued neglected Cockatoo's that have lived in deplorable conditions and need a lot of TLC to get them back to enjoying life and wanting to wake up each morning. I myself have just one Cockatoo, and she is a handful all by herself. In my situation, I could not take in another bird of any species right now, but I sure do applaud those of you that have. Your actions, patience and committment to these birds is outstanding. No matter how much we can provide for our birds, (every household & situation is different) it sure is better than a bald Cockatoo (or any bird) locked in a garage in the dark all by itself. Hat's off to you guy's.