For some reason I can't post a new thread, so I choose this one as what I think is closest to my situation.
I have four hens ranging from 8-9 months old. They have a coop in my backyard and 'free-range' all day at will. They have been very happy and active every since we've had them. Penny (the Speckled Sussex) has been normally very friendly and usually the top of the pecking order. However, we noticed several days ago that Penny had lost some feathers around the head/neck area though seemed to be acting normally initially. Over the next few days her comb became 'less red' and the other ladies began to peck on her. She, for the past few days, has not left the coop and just sits in the doorway area. She kinda puffs up and sits, not aggressive but makes some small squeaks when I'm close by. I have seen her walk down to get food and possibly water, though she actively eats some tuna form my hand. Poop appears to be normal, not sure if she has been laying because I can't tell the eggs apart.
They all have access to pellet feed for layers, water, and oyster shells. Each day I throw out some cracked corn or wild bird seeds. The weather very recently has gotten super cold and obviously the daylight is much much shorter these days. I do not have a light for them.
Can this be molting, especially at this age? Maybe a 'soft-molt' as this site describes: http://msucares.com/poultry/management/poultry_feathers.html ?
Her inactivity worries me, not sure what do do. I've brought her in the house for a little bit, it that bad? The house is nice and warm and its very cold outside (I'm in Montana and its been hovering between 0-10F day and night. She seems so inactive and such that I've seen her 'shiver' a little bit (if chickens even do that).
Any input would help, thanks in advance!