This is why some people encourage crows to stay around. While crows may get the occasional chick, they leave full sized birds alone and chase off hawks.
We lost a duck to a red tailed hawk and have really encouraged the crows since then by putting corn out for them. This is an imperfect defense against hawks as the crows come and go, but I’ve seen the crows chase off hawks many times now. My guess is that encouraging crows still allows the occasional soaring hawk to hunt, but really decreases the likelihood that the hawk will ambush after watching from a tree.