Broken and missing feathers at base of tail on two hens, HELP!

[cknlvr]

First post here. Unfortunately its not for a good reason.

I have 6 hens (no roosters), 3 Orpingtons and 3 RI Reds. They were hatched last spring and have been healthy and laying well up until this point.
On Wednesday, I noticed 2 of the three reds with scraggly looking tails and gave it some notice, but was not overly concerned.
Today, it seems both hens are missing more feathers and there is some exposed skin on both.
Behavior is normal from both of them in so much as they have normal droppings, are continuing to eat well and have a good color.

Things I've investigated:
Mites - Haven't seen any of the creatures around the vent and skin color looks good. Also, its not effecting the other 4 hens.
Abuse - Possible, but I have not observed any negative behavior from the other hens during any interactions. None of the hens have gone broody to my knowledge.
Molting - Can't see any new pins to replace the missing ones and all the loss is in a single area on both hens.

Background Info:
They live in a double decker "condo" that is open on the bottom, closed in at the top and is 3ft off the ground. I use a sawdust and straw mixture for bedding and feed them organic layer pellet with oyster shells and flax seed. The bedding was removed and replaced last week.

I'm out of ideas at this point and was hoping someone could assist.

Photos below:

 

[heritagebirds]

We get that from overly amorous roos...but I don't see that you mentioned any roos.

 

[cknlvr]

Quote:
No roos, forgot to mention that.

 

[Guwisti]

I would think pecking. I have 6 pullets (almost a year old now) and no roos. We have one hen who has basically become the roo, she guards them when they're roaming around outside and she is quite literally at the top of the pecking chain. She pretty much pecks anyone in her way. At the other spectrum is one of them who everyone pecks on. She quite often looks like this, always a pecked pretty clean place at the base of her tail. The others don't show too much pecking damage, except for low girl on the pole. I know you said you don't see any aggressive behavior, but I'd almost bet that's what it was. Watch really close at feed time, if they have to vie for space, and see what happens.

 

[cknlvr]

Quote:
So if they are being pecked, will it develop into anything life threatening? Should I be concerned or will it just ebb and flow?

 

[cknlvr]

The condition is worsening. Does anyone have a suggestion as to what I should do?
If this is abuse related do I need to separate the effected birds?

 

[buffy O's]