Turken Feathers

[Nike]

Hey I have a turken and you know how they have little tufts of feathers on their necks? Well I have this one hen that has been plucking them off. Is there any way to break that behavior? They are almost 13 weeks old as of tomorrow. Will it go away while the turken gets older? Both birds are nice and beautiful and I don't want to sell either. Is there something I could put on it to make her not want to peck it? Please help, thanks.

 

[Nike]

Oh also I have a 6X8 coop and twenty seven 13wk old chicks in it. They are free ranged and hardly ever go in the coop so I don't think crowding is part of the problem.

ETA: I've only seen this hen do that to the turken, no one else plucks feathers.

 

[Nike]

does anyone have any ideas????????????????