I don't know. I have lots of crows daily and a few ravens even. And I still have hawks and the rare hawk attack.One of the TSC employees solved her hawk problem by feeding the local crows, away from her coop. She hasn't lost a chicken to a hawk in 2 years. (I didn't ask her about other predators)
I am thinking of putting out a bird feeder on the opposite side of my property from my garden and coop and try and draw some crows in. Fill it with cracked corn instead of birdseed so only the large birds are attracted to it.
The crows and the ravens feed right along side the chickens.