I think it may have been a Red-Tailed Hawk, also sometimes known as a...chicken hawk. Uh-oh. I think it was fairly young as it was pretty small and the noises it made were young sounding. Hey, I have birds, I know the difference between a young chicken sound and an old chicken sound, hawks can't be that different, right? My hawk didn't have a white breast but was speckled sort of all over.
It was so pretty I couldn't help wanting to get as close as I could. It didn't seem scared of me at all. In turn, it didn't phase the chickens one bit. I guess if they felt there was a threat to their safety they would be hurrying to get under cover.