I'm sorry you lost 2 chickens to the hawk, was the 2nd one a white silkie also? It seems that white/light-colored chickens are special targets, as well as those who seem to be more vulnerable, the small & young, the sick & injured, & the otherwise slow-moving. I try to discourage our resident hawks by hanging shiny moving things around & over my chicken pens, CDs & DVDs, dollar-store wind-catchers, and pinwheels. A neighbor who keeps pigeons places mirrors on the roofs of his bird pens. I also protect my birds by providing places for them to run into & under, and keep roosters. The roos have a bird-word they say when anything flies over the yard, and they have an especially bad word they say when they see a hawk. When they say that word everyone stops, crouches, looks up into the sky, & runs for cover. I wish you success in keeping your flock safe from hawks.