I had a hawk kill one of my silkie chickens in October, we strung up fishing line all over the top of my chicken yard, which is too large to put netting, and also strung up reflective cds. Everything was fine until last week, the clever hawk learned to land on the top post of my chain link fence, dive under the line and chase down my chickens on the ground. I was alerted by my guineas and ran out there and saw the hawk attack a favorite silkie rooster, I grabbed a rake and ran after it, it saw me and was clever enough not to fly up into the fishing line. It got to the fence saw a place to get to the top and got away. My rooster was dead. A little while later I saw it sitting on the top post looking for the chicken it had killed. I chased it again and my chickens have been locked in their coops ever since. What can I do?