:aww I am sorry about your losses, both bird & animal.
We have red-shouldered hawks here that have gotten a few of my chicks & chickens over the years. I've also lost a chick to a small kestrel one Christmas morning, and I think an owl took a small rooster sleeping on a fence one night.
I have 6 roos with my flock, they are great for signaling a warning. They have one word for "something flying overhead" and another particularly bad word for "hawk!" When they say that word, all of us in the yard, bird & human, stop, crouch, and look up in the sky. Then all the birds scoot under the nearby bushes & yard furniture. All the roos and many of the hens squawk bird profanities until the danger passes.
I keep shiny moving things around & over my runs, old CDs, pinwheels, sun-catchers from the dollar stores, etc. I like to think that helps, the bright moving flashes reflecting the light rather than any certain warning color. It also helps to have things around in the yard for the chickens to hide under, patio tables & chairs, pallets or plywood up on blocks, rusty old pickup trucks without wheels on cinder blocks, etc...
The hawks here seem to prefer the chicks, and any lame or disadvantaged birds. They've come to the ground to land beside pens of chicks left outside, and have reached through the wire and killed one. Now when I keep chicks outside I cover their cage with plywood and give them places to shelter in the center of the pen.
The saddest loss I suffered was a dear little mixed-breed hen we named Quiche. She was nothing to look at, but she was a superior broody Mama. I think she died defending her last 4 chicks from a hawk, they were huddled in my butterfly garden & she was nearby in the hedge, already dead & getting eaten by this hawk.
The Big Decision is how much you're willing to risk an occasional loss to hawks for how much free-ranging you want for your birds. And how much you're willing to risk letting them free-range unsupervised. A lot of that depends on how prevalant the hawks are in your yard, and how much time you're able to devote to supervising your flock. For me, I just try to give them lots of shelter to escape into and trust the vigilance of the roos & mama hens.
