Hello!
First thing, take him to a avain vet. His plucking could be a due to a medical condition.
African greys can be a nervous bird. They do not deal well with changes, especially major changes. Did you maybe change his location in the house? Can he go back to the location he was at before? Any new additions to the family? Things like that.
seeds are ok to give, but make sure its not the main dish. They need friuts & vegetables, pasta is good to give. brown rice & beans (pinto beans,lentils, green split peas) I use a pasta & bean soak. Its called bean cuisine by L'avian, it has pasta, rice, & beans in it. Its excellent for them. I also give my greys chopped up zucchini, yellow squash, apples, & bean sprouts. I use a frozen bag of mixed veggies that I defrost in slightly warm water ( do not microwave or cook) that contains peas, carrots, corn, & green beans. I add regular cheerios to their food bowl. I also use roudybush" pelleted food. I do offer a parrot mix with the seeds so they can have some "fun" foods, but as you can see its not their main diet.
Some times if there something missing in their diet, that can make them pluck. Also, don't pay attention to the plucking, ignore it. Sometimes if you react to it, it will only reinforce the habit.
All in all, you could be "stuck" with a plucker, just make sure you give him lots of love & attention! Good luck & I hoped this helped. Let me know how it goes for you.
Read this: Avian behavior
Hello again,
Beatriz, that was an excellent article! Thank you!
Just for the record the roudybush pellets I use are organic, I shoul of mentioned that. For the calcium, I sprinkle crushed oyster shell on their food. I also sprinke Quiko which is made with real eggs over the food to. cause egg is also good for them.