The enemy of my enemy...
The songbirds are nesting in my neighborhood, too. Today, I watched two, a mockingbird and a grackle, fighting over ownership of a choice piece of high shrubbery, suitable for a nest. The fight was interrupted when a raptor flew nearby, and the two birds postponed their turf battle and ganged up on the intruder, dive-bombing it repeatedly until they had driven it away.
Nature has lessons, for those willing to learn.