Do cockatoos grow their feathers back after they pluck them?

Cockatiels (not the fish but a small parrot species belonging to the cockatoo family) can regrow their feathers once they molt (loose their feather naturally) or it gets plucked. But if a cockatiels’ feathers are severely plucked, they may not grow back if the follicle is severely damaged. For minor plucking, it may take a few months to a year for them to grow back. Cockatiels may pluck their feathers for a variety of reasons, including stress, boredom, illness or trauma.