Pastured poultry/Hawk food

I wanna say that free range pastured poultry is a problem free method of chicken propagation.  Using electric fencing protects from surrounding terrain but leaves the sky open to intruders.  It doesn't cover the chickens in case of hawk attack.  The field I have the chickens in is in a "holler" surrounded by trees, sounds great you say? It's like running the gauntlet says the chickens.  Since the begining of my chicken raising career I have lost chickens to a host of things all with their tell tale kill methods.  The Hawk though seems the most magical in it's method- they just disappear.  I haven't ever seen a hawk attack, those hawk eyes know when I'm lookin'.  But Gramma saw one taking a dive off a tree day before yesterday, headed behind the garage where the chickens hide out.   That evening when we went to put up chickens for the night good ole' blackfoot was missing.  She was mean as hell and i'm sure got in a few licks before going down.  Or up as the case seems to be.  After several of these disappearances during the daylight hours I must admit defeat. In my situation I'm afraid that the chicken tractor is going to be the only way to raise chickens without keeping a good many for hawk feed.  Don't get me wrong, I love those things, but is there anyone who knows of a chicken protecting dog or donkey/dog mix that will allow the pasture raising of chickens?

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