I forgot to add to the OP that I hope your missing chickens are just scared and hiding somewhere and they will come back home, soon.
Chickortreat, I understand the dilemma. In my opinion and observation it has more to do with the history of how raptors were treated in the past and that's why they're all protected now as a group even though many are numerous. I know that they do review the lists of other birds and remove them from being endangered, but I think there's something different about raptors as they're all protected as a group.
They could be hiding and it could be more than one hawk or more than one type of predator, just a bad day. Sounds like the buff may be gone though. Were there a lot of feathers?
Thanks to all who posted...Good News, they are home! We could not believe it...the rooster was back at the coop when we went back out at 4:30 today. My daughter and I then went to the woods at the very front of the property shaking the grain can where we found the Buff Orpington feathers and out she came from the other side of the fence! We kept looking for the barred rock, shaking the grain can and she came out. They were scared to death. The buff looks ok, just missing feathers, the barred rock and rooster are fine. We have 20+ chickens & 13 guineas, everyone is safe in their coop tonight!
My Great Pyrenees is usually excellent at keeping predators away, he recently chased a hawk away that was in our riding ring with two of my americaunas . It amazed me he knew that the hawk was not suppose to be with the americaunas! Anyway, I guess today he was trying to stay out of the sleet/freezing rain and didn't realize what was happening until he followed us out the barn. In his defense he did run up and down the fenceline where the chickens were hiding! Our Pyr will be two in February and we have not lost any guineas/chickens since he was 5 months old! Before getting him we had fox, raccoon and oppossum getting our flock...so he is doing his job he just took a little break today!
Fantastic.
I'm always amazed when 1 or 2 don't get locked up at night and appear a day or two later.
Makes me wonder why I invested the time and money in a coop. LOL I should have just let the brush continue to grow.