The fishing line and shiny things does work, and it does run the risk of entangling the predator. A neighbor uses it quite successfully, and once the bird has a bad experience and knows it’s there they generally move on. If you use this though, you need to be prepared to deal with releasing a very pissed off, possibly fairly large bird with nasty talons and a hooked beak. Chances are they will not know you’re “helping” them and they will be fighting (you) for their life.
Husband was over at said neighbors on other business, and they had the pleasure of experiencing this firsthand. Hawk was released unharmed and has not returned. Welding gloves and a towel were employed in the release. We don’t really have a hawk problem here though... eagles and ravens for the most part, and I will not mention how we (legally on this registered farm in Canada) deal with them here as it gets everyone too riled up I’ve found. I prefer the Golden Eagles personally, they are larger, but not as likely to maim and kill the lambs (70 as of today and counting!)
Husband was over at said neighbors on other business, and they had the pleasure of experiencing this firsthand. Hawk was released unharmed and has not returned. Welding gloves and a towel were employed in the release. We don’t really have a hawk problem here though... eagles and ravens for the most part, and I will not mention how we (legally on this registered farm in Canada) deal with them here as it gets everyone too riled up I’ve found. I prefer the Golden Eagles personally, they are larger, but not as likely to maim and kill the lambs (70 as of today and counting!)