On my way into the pen I found this:
When I got to the bird laid out on her back and touched her feet to pick her up, I realized she was very much alive. I picked her up, holding her gently, not knowing how badly she might be hurt. I tried enticing the other two to follow me with the dog treats in my pocket. Dogs. The dogs had hung around, probably more fascinated with the chicken frenzy than loyal to me. Dogs go inside; injured chicken goes in a box for the moment, with water and food. I didn't find the neck injury I'd assumed she had, but she was missing some feathers, including a bare spot on her neck.
Back outside I had more success getting the other two out of the pen. I walked around counting. Eventually I located all 13 red hens, both roosters, the Speckled Sussex and 3 Favarolles. One Favarolle and 2 Barred Rocks missing. The Barred Rocks are older girls. They know how to hide. I wasn't worried about them, but assumed the missing bird was one of the smaller, meeker, younger Favarolles. I prepped the "chicken infirmary", a small wire pen we keep on the closed-in side porch for sick or injured birds that need to be isolated. Plastic liner in place, a layer of wheat straw with bowls of food and water, and she has a place to stay for a day or two. I examined her again and still found no real injuries other than missing feathers. Joan reminded me that passing out is a fear response in chickens, though not really a survival skill.
I went back outside and walked around the pen and along the road on the other side of the pen, not finding the trail of feathers I expected. So many feathers in a large area with no carcass could only be a larger animal, i.e. not a hawk, like a dog. This is worrisome because a dog that is able to feed itself well on one bird will be back for more. But then, heading back to the house, I discovered all 4 Favarolles casually scratching around together like nothing had happened. Both Barred Rocks showed up as well. There were no missing chickens. So my poor little red hen must have lost more feathers than I realized. I still don't know what happened to her.
To celebrate all birds still alive, I dumped a bunch of veggie and fruit scraps out for them.
Happy birds, happy farmer.