I am not sure why chickens wait until fall and winter to moult here, but it seems always to be the way it goes at my place . Right now I have two birds moulting. They look like they have been in a “cat fight.” They are also hesitant to come outside the coop. It is like they are embarrassed to show the world how they look.
For those of you unfamiliar with chickens, it is when they lose all their feathers and get new ones. It happens about once a year. During that time they will put their full energy into getting new feathers and their egg laying will slow down or cease altogether. Some birds moult slowly and it takes 2-3 months. Fortunately mine seem to go through the moult cycle fast and furious. One day I open the coop and it appears that a pillow fight ensued overnight, and a bird looks like they were in a fight and got the short end of the stick.