I also live in a suburban subdivision with farms nearby. We have Cooper and Red-tailed hawks. My ducks have been free ranging for five years without incident (although I have found sparrow feathers more than once from Cooper!s hawk kills in my yard). I think one thing that has really helped is the neighbors purple Martin houses. They have two, right next to the property line. I have seen the martin’s attack Red-tailed hawks and Great horned owls who venture too close. The martins are only around in the summer but that is when the raptors are nesting and most desperate for food. So, I would make sure they have shrubs to hide in and put up Martin houses.