I've lost two hens over the past week. Heads picked clean except for combs, breast feathers plucked & meat eaten down to the rib bones. I'm almost certain it's an owl because I saw one a few nights ago on a post in my vineyard. The chickens are in a pasture surrounded by a 6 foot fence (combination of sheep & goat fence and electric poly wire). Short of closing up the coop at night, what else will deter it? I'm thinking of putting motion-sensor lights on the coop.