Birds eating their own tailfeathers?

[OldChurchEggery]

I have a group of 5 month old birds that have been doing something very strange. Every evening when I lock up their coop (they get to free range during the daylight hours) I notice little drops of blood coming out of feather stubs around their tails. They are fed scratch grains on the ground, layer/broiler crumbles (Superbreeder from Southern States), and as I mentioned they get to roam around our 8 acres as much as they like. I can\'t see how it would be some nutritional deficiency or boredom leading them to do this, so I am wondering what the cause could be. The Ameraucanas are being raised with a pair of Jersey Giants and two Australorp pullets that are the same age. The Jersey Giant cockerel is big but is quite low in the pecking order, so I don\'t think he\'s the culprit. If it helps, there are 4 Ameraucana pullets and two Ameraucana cockerels. The Wheaten cockerel seems to be at the top of the order, but even his tail feathers are missing. Could they be eating their own feathers? Any advice on how to get them to stop?

[OldChurchEggery]

To clarify, only the Ameraucanas are missing the tail feathers. The other breeds look fine.

[Mike Gilbert]

Of course their tail feathers are being plucked by other chickens.   If they are all running together, it is likely the ones without the missing feathers are the culprits.  But you need to spend some time watching them to find out for sure.
Once they get started, there is little hope as long as the feathers are juvenile.   You will need to separate the victims until their tail feathers are mature, then the others will probably leave them alone.  That will take a considerable amount of time, I would say perhaps six weeks.

[OldChurchEggery]

Thank you for the advice, Mike. I\'ll have to separate out the injured ones this weekend. Do you recommend anything in particular be put in the bloodied quills to keep them from pecking at themselves while they heal?

[Mike Gilbert]

I use a Farnam product used on horses for cuts and wounds to prevent proud flesh.  It is called Wonder Dust.   It has quite a list of ingredients, including activated charcoal and copper sulfate.  It comes in a plastic shaker bottle.

[Paul]

Petroleum jelly-vaseline-can be rubbed into a birds plumage, then heavily dusted with sulfur will usually put a stop to feather picking.  It may cause staining on some varieties so it must not be the adult plumage if you are going to show them.