My husband and I just witnessed our local crows defending our chickens (well not directly). A large red-shoulder hawk was perched in the top of a tree only about 75 yards from our chicken coop. A lone crow was harassing the hawk, cawing and swooping around the hawk. The hawk didn't move. However, in just a few seconds, 2 more crows showed up and the hawk bolted. After a victory lap around our yard, the crows took their leave. Thanks crows!!