Lorikeet feather plucking problem

[BigBird]

I bought a red collar lorikeet last week that has a feather plucking problem, and has pulled out most of his chest and around back of his neck. The previous owners said he started doing it when they went on a holiday for a month.

Is this condition reversible? Do you have any experience of them changing this habit. He is now in a new home, about to go into a large aviary with 7 other birds of a feather. Do you think this will make him forget about his plumage or is he most likely to continue plucking them out?