@evilmonkey239 The lack of feathers, especially head feathers, is a likely indicator of disease. It looks like they are feather plucking as well. A real shame for the only members of their kind outside Puerto Rico.
@Great Argus The parrots are not diseased, but they are both behavioral feather pluckers. The balding on their heads is due to both picking the other, but as it is not aggressive (these are two bonded males) they are kept together. I'm unsure if the facility is doing anything to reduce the behavior.
@Sheather Thanks for the additional information. Good to hear it's not disease, unfortunate such rare birds are feather-plucking though. Disease was my first thought as the heads were affected, I haven't heard of too many cases of non-aggressive feather-plucking. Hopefully the behavior can be discouraged somehow.
@Great Argus With parrots that have this behavior issue, it's a sort of compulsion. They do it to each other clearly, but as they like each other, they don't seem to mind it... it suggests that something in the parrots' lives was lacking at some point but feather mutilation is almost impossible to stop once the pattern begins even if the environment is improved.