My budgie, Benji was in my room, with his cage door always open. When winter hit, my room started to get damp, and I found there was mould growing, so having to clean every couple of weeks. Benji's cere started to go dark in colour, kind of a dark grey / black, or blue? Can't remember... So I moved in with my father, and he had to go in the aviary. His cere started to go normal again, but lately it's a brownish, flaky like. I don't believe that is normal for males, as other ones in the past never had that issue. Is he sick, or am I just over-reacting? He is just over a year old, wild Budgie.
He is still eating, and isn't loosing feathers.
Picture was taken yesterday.