It finally happened, after ten years of raising chickens we have suffered our first lost due to predation. We believe it was a bobcat. We have a row of trees along one side of our chicken run and one tree inside the run, The run has a 8 foot high fence around it. I found deep claw marks in the trunk of the tree inside the run and one of the trees outside the run. No sign of the hen except a lot of feathers inside the run and a trail of feathers leading into the under brush. I've installed 6 foot tall sheet metal collars (4 feet above the ground) around all the tree outside the yard. Hopefully this will keep our rare, if unwelcome, poacher out.