How can I stop an African Grey parrot from plucking feathers

Yesterday I gave a parrot a home because its current owner had a young baby and could no longer spend the time she used to with the parrot. The bird had been plucking its feathers and the vet says there is nothing physically wrong - it is heathly.

We brought the poor bald bird home and set up its cage in the conservatory so it can see outside and it appears to be contented.

I am looking for advise on a couple of things (I have had cockatiels and budges so have plenty of experience of looking after birds).

How do I stop him pulling out his feathers - I've never come across this before.

And he has been a free flyer up until now, however he poo's everywhere. Is it okay to let him out for a while then put him back in his cage?

"fenlandfowl" has the most comprehensive answer here, really.

I attended an Aviculture Federation convention last year. One of the speakers was Dr. Susan Clubb who has been doing research on feather plucking. The discovery of subcutaneal bacterial and fungal infections was found to be a major player in many instances of initial plucking. After the initial problem has been addressed, the "habit" of plucking might still remain.

As is the case in just about anything, ruling out a clinical issue is job one.

After that, you have to start working on the diet, and then the environment.

As for the diet: go very heavy on the dark green and dark orange vegetables: broccoli, kale. yams or sweet potatoes, turnip greens, carrots etc.