Feather Question

by Dolly
(Sacramento Ca)

Just recently got a scarlet Mccaw. Noticed some of his feathers were laying down and some are standing up, especially on his back. It is obvious he has plucked his chest at one time, the feathers there are growing back. But all still look ratty, even tail feathers. Could this be because they moved him when I got him, Does stress cause these ratty feathers/ I don't know what to do any ideas?