I had a young hawk eyeing my birds. Only noticed it because the roosters did the "danger" call. I saw it and walked over to where they were and just stared him down. He flew off after a minute or two. Haven't seen him come back since. Our dog is a recent addition to the family and up until then our biggest problem was raccoons. She has managed to chase a few off and a few possums. We have plenty of cover for our birds to hide under if there are hawks around though. If I notice it is really quiet I yell "HEY YOU CHICKENS" and they all run under the porch. Now that we have a roo though he alerts the hens. Havent had a hawk attack yet this year but our first year a red tail came after them. They ran under the porch as he swooped down and then he took off empty talonedMy chicken area is about 1/2 acre fenced, the only cover come from the trees. I don't have an outdoor dog but I do have pet dogs (two females and two males). The male dogs do not get inside the chicken area without supervision. These are the things that I think it has helped me keep my flock safe from aerial predators:
I have three turkeys (adults) I am assuming this will intimidate an areal predator
I have 7 adult ducks. I have seen them alerting the flock when they see a hawk.
I have 3 adult roosters who protect the ladies.
I also allowed my two male dogs go inside the chicken area ( supervised by me) to leave their scent. I DE shed them and leave some of their hair in the fence and also they urinate in the area . I have heard that male dog scent will deter ground predator.
So far this has helped to keep my flock safe. I only had one accident last winter and that was because the trees give no cover at all.