Found out that if a vultures are hungry, they will attack and eat chickens. I've had 3 that have been eyeing my chickens. they swoop very low down but my dogs have been doing a pretty good job at keeping them away, However, my dogs aren't always outside and I'm worried that the vultures might try to take one of my chickens as I had one of my favorite chickens go missing without a trace recently (which was most likely the result of an areal predator.) How can I keep them away from my yard?