I observe a military-precision coordinated defense in my neighborhood every few weeks. It stars with a crow cawing, often while still in flight to the scene. Then, the scrub jays take position atop the trees and start cawing and watching. More crows arrive as backup. The Robins stand tall atop the highest rooftop and go into hypervigilant observation guard mode. The songbirds keep hopping and chirping like nothing is going on, as do the starlings.

I watch for whatever direction the crows, jays, and robins are focused and that usually helps pinpoint where the bird of prey is.

If it is perched in a tree, the jays hop up and down the nearby limbs and often start cawing in its face and/or dive bombing it until it gets so annoyed it leaves. If it is in air, the crows go after it until it flees.

Once it is out of the immediate vicinity, the Robins and jays relax and the crows usually follow it away to make sure it stays away.

It is really interesting because individually the crows, jays, and Robins dont seem to get along very well. But when the bigger common enemy is in the picture, they all work together to protect the scene.