McChooky
Free Ranging
People who genuinely care about their birds and supervise them rarely lose a lot of birds.Not saying it can't happen but predators watch us as much as we watch them. Its when we leave them unattended and are gone a lot that the worst attacks occurEven though your chicken didn't have obvious wounds, you may want to treat her for shock if she is acting off, not eating or drinking normally.
Aerial predators will always attack from above: hawk, falcon, owls. I can tell you hawks and owls will swoon in silently. You may not always hear their approach and if they are on glide mode, you won't hear their wings beating. Yes, owls are out during the day here also. Everything is hungry.
One day out of the corner of my eye I luckily saw a hawk making a silent nose dive into the yard. I jumped out of the shadows in a bee-line for the chickens flailing my arms which surprised the hawk who made a fast 90 degree turn and flew away. It was only about 15 feet above the chickens. Unless you have a rooster, a dog, or you are the rooster, chickens cannot always run for cover fast enough and do sometimes get surprised despite being naturally sky aware.
After reading about the various predation injuries on this site, I'm paranoid and now won't leave them in the yard alone at all.