My husband and I have just spent a few days stringing monofilament line over the open area in our orchard, bearing in mind that there will be less cover this winter. Monofilament strung up 8-10 feet up at 2 foot intervals will deter most hawks. Use the shiny, clear, 40 Lb test. It will sparkle in the sun.No raptors will risk their wings in it. They use this in Fla. to keep seagulls off the balconies too. Leaves will not foul it as they will netting.
Thanks for answering, DL.
So, this is fishing line. Should I use a colored one? I guess a hawk's eyes are better than mine. Hence 'eyes like a hawk.