I use whats called "wildlife" netting, we have lots of hawks too. Its very thin, supposed to keep birds/rabbits out of gardens, if a hawk wanted to break through it, they could, but they would more than likely end up wound all up in it and stuck...that stuff catches on everything. I havent lost a single bird to predation since putting it up, I lost 3 to hawks last year, and a couple to weasels, I tie wrapped it around the whole interior of my chickens fence, so small things like snakes and stuff cant get through the wire, Ive actually had 2 snakes get caught in it and die, well one died the other was almost dead when I found it, and its super cheap, like $12 a roll at lowes, if you just need a giant square, the size of a large tarp its around $5 I think.