Missing neck feathers on a GLW Roo (Bald on both sides !?!)

[funnybirds]

Hmmm, no idea whats going on with Nucky the roo but he got out of the coop yesterday morning with missing neck feathers, on both sides. Its been raining, I just cleaned out the coop (every two weeks with pine shavings and DE). All food and waterers are totally cleaned every day, and they range when the sun is up til its down, rain or shine.
Any ideas?
He shares a small coop with an Ameracauna Roo who appears more dominant and full of himself and a hen. They don't appear to fight at all, are about 5 months old (If I recall correctly)and spend their days lounging around and ranging.
Any ideas? he looks very bizarre but acts just fine and all else appears to be normal. His tail feathers aren't all they great either. Never has developed a full roo style back end, but I have attributed this to his young age, although the other roo has a very full and gleaming tail feather set.
Sorry I tend to ramble, but I wanted to provide as much info as possible.
Thanks!

 

[Judy]

A possibility is mites/lice; a dusting with poultry dust would be a good idea anyway, as they are all going to get exposed, they come from wild birds. But I really think this is the result of his being the #2 roo plus teenage hormones kicking in. It is possible that increasing the protein in their diet would help, but that would not be my first guess. You said they share a small coop. That might be the crux of it, too, or a strong contributing factor.

 

[funnybirds]

I checked for mites and did not see anything. I will happily dust with a medicated powder, but which one? Also what do you guys use for worming? How much, how often?
These guys are still young (around 5 months) but I wanted to catch any before they begin to lay, or procreate...
Could Nucky be just molting? When do chickens start their first full molt?
Thanks in advance.