I recently (two months ago) moved my flock of chickens from my home to my mother's. They're in her barn. I have electric netting all the way around the barn. In addition to the fencing I have a Pyrenees/Anatolian Shepherd mix dog outside at night. The fencing was great at my house. After I put it up, I didn't lose a single bird to predators.
Now I'm losing quite a few, and it seems to be getting worse. I'd estimate I've lost ten birds since I moved, with the numbers increasing recently. That includes two rooster - my head rooster who was 2 1/2 years old and a youngster of about 6 months.
I lost an old white Plymouth Rock two days ago (the same day the younger rooster disappeared). I can see the spot she was killed just inside the door to the barn.
I'm not sure what time of day I'm losing them, but I think it's night time. Twice I've heard a racket at about 9 pm and went to investigate but found nothing.
Whatever it is is undetered by the fence and takes the bodies away with it. Twice I've found the poles where the two ends of the fence meet pushed apart in a V - like something had come in that way. I've fixed that, and the killings continue.
The chickens are seeking higher roosting spots in the barn. I don't know if they sense something is prowling around at night?
I may get that camera someone recommended in another thread.