I'm trying the fishing-line deterrent. Bought 2 spools of 15-lb-test monofilament, 170 yards each, for $2 each. The chicken yard is fenced with T-posts and plastic deer fence 6' high, so I strung the line from the tops of the T-posts back and forth across the yard, criss-cross and diagonal. I threw the line over the branches of a tree to pull it up high enough so it doesn't get me when I walk into the yard. Because the posts are 10 or 15 feet apart, the pattern has holes plenty wide enough for a hawk to fit through, but we'll see. Coopers Hawks attack laterally, so the fishing line should look pretty dense to them. Even Red-Tails aren't likely to strike straight down, so I think it's OK to have fairly large gaps as long as there's enough line up there to distract the hawk from its pursuit. I might hang some CDs from the line to add to the distraction.
Netting would be a more certain solution but it's not available locally, and a lot more expensive. The yard is a little more than 50 feet across and irregularly shaped, which would make netting difficult to use. I really hope this works!
