hollowing bird

Question
I have a cockiel bird about 3 yrs old,he has started to hollow a lot lately,especially when I leave the room,sometime when I enter,what would cause him to do this Thank you if you can answer this question.  

Answer
Hi, Shirley.  Thanks for posting your question.  Your tiel is trying to tell you that he doesn't want you to leave the room!  He hollars when you enter because he is glad to see you!  He doesn't want you to leave because he wants your attention (because he loves you) or needs something, such as food, water, a treat, clean cage, etc.  

Chrys