Fixed
Currently Domesticated Tallbirds will Aggro onto every mob except you. Working on changing this targetting behavior.

Edit: This behavior has been fixed. Domesticated Tallbirds will only Aggro onto Monsters, and will leave Small/Teenbirds alone, and leave Chester alone.

When a Domesticated Tallbird is not with you when you are exiting a cave (Tallbird in a pen so it did not follow you to the caves entrance), it will stop following you, but is still Domesticated. Working on this issue.