I first noticed the missing feathers this spring and assumed they were molting (still not sure what that looks like). My oldest guinea, 'Keet', lost a clump of feathers in the same area the end of March, early April, at the same time finding his first mate. (I stole her eggs and incubated them.) Feather loss is not as drastic on these other guineas. It could possibly be different guineas I'm seeing, but I would think they would all 'molt' at the same time. The surrounding feathers are tattered. Is it possible I have another problem such as mites? I presently have approximately 40 Guinea in my flock, but only a few of the 1 year olds are afflicted. Nobody is itching. Everybody is still chasing and breeding. That being said, I would venture to guess that most of the Guinea's missing feathers would be the males. Maybe they are lacking something in their diet? If you are fortunate to have knowledge or expertise in this area I would greatly appreciate your wisdom.