Something certainly does seem out of place the way he holds his tail. Hopefully he will perk up tomorrow morning- chickens are emotional, could it be he misses the other one?The coop he is in only has two other birds with him (one a week younger who I'm unsure of the sex, and a pullet who is very motherly to both who is 14 weeks).
However when they are out of the coops all the birds are together so I thought it could be due to the fact that someone ruffled his feathers while they were all out together.
Still just wondering if it could be anything else I really need to be worried about health wise as I feel he is content in his coop with the two other chickens