Do know what's going on?

[mymilliefleur]

Hmm...sounds like you have a predator issue. Do you have place where you can put where they will be safe? Certainly check into the Emergency section ASAP. Good luck with your flock.

 

[DuckyGaze]

Welcome to the best and most awesome poultry forum there is!

I have alot of experience with ermines... all my hens and roosters are dead now and I just do not have the heart to get more and see them suffer but
each time I found 1 dead, it was missing feathers under the wings and on the belly. Also there was a mess of raw tissue especially under the wing area.
I did have one rooster that was torn up badly under the wing, had no more feathers on the underbelly and I had to ask my hubby to put him out of misery.
An ermine got in the pen and killed the last hen and tore up my poor rooster badly. The ermine will also attack the head since it is the brains they prefer
to eat. So that rooster had no more comb and both eyes were out also... a bloody mess.
Ermines are hunters that bite and grab and go on for a long time before a chicken, goose, duck or other poulty will die. They like to eat the brains and
they actually leave the rest of the carcass.
I actually lost 2 ganders to this ermine also. My beloved gander was not dead when I went out in the morning but he was taking his last breaths.

You need a trap or you really need to make a secure pen for your poultry.

I was fed up with this ermine but did not have the heart to kill it so what I did was build an 8 feet by 4 feet shed that has roof and floor. The door is also all
wood and locks so in the evening when it begins to darken I just lock up my ducks in their shed and I have another huge unused dog house that I put a
door on and the geese are locked up at night in that one.

It is the only sure way of keeping predators from killing my beloved pets.

An ermine and most weasels can enter a pen through a hole about 1 - 2 inches in diameter so open air pens with meshing is risky.
Then there are the foxes and racoons that can dig to get in a pen. And there are eagles and falcons that grab poultry if there is no roofing.

Only sure way of keeping poultry 100% safe is to put them in completely closed wood sheds. I have a friend that used an old aluminium garden shed
and that worked great also.

Also if you want to set a trap to catch an ermine or weasel there are some very simple and safe ways to do it. Just google.

 

[Weehopper]

Have you checked all around the claw marks for holes that would Iindicate bite marks also? Sounds like infection going on there if it appears she may be losing the wing. As to what did it, hard to say. There are a few preditors that can claw. I don't see other chickens clawing as such. A scratch maybe if the one doing it has very sharp spurs. But even with a sharp spur, you are more likely to see holes than claw type marks.
I would be looking for pretators.