Cathy, we had quite a few hawks in our area and we did ask around and got a couple suggestions.
1) hang a mirror type windchime.
2) use a garden mirror globe in the center of your yard
3) Those little scarecrow people.
The mirror reflection usually will deter them, and if all else fails get one of those airhorns and blow it off when the dogs go outside. ( my bet is your neighbors wont like you very much )
VCS TSD10 Mirror Ball 10-Inch Turquoise Stardust Stainless Steel Gazin