It depends on the bird so I can't give you a definite answer. But it could range any where from a few weeks to a few months. It's like you just took a real bird away from him. My bird Kirk used to cuddle with himself in the mirror and started to only eat, drink, and look at the mirror. I threw all the bird mirrors out because it seemed unhealthy to me for him to not get an exercise and to be so focused on one thing. It probably took him a few weeks, maybe a month to act normal--but he didn't call for it when we took it away like your bird did.