The Question of Strange Bedfellows

Is it sport, warfare, or a love affair? A crow and a mockingbird fly together across my watch several times a day. I've seen them every day I've been at the lake. They fly beside the lake but not over it. At first I assumed the mockingbird to be chasing the crow from a nearby nest. It was always a few inches behind the crow, they always flew in same direction across my porch view, the mocker would turnback at a certain point, and the crow flew on. Now I think otherwise, because I see them so often, and because the mockingbird doesn't always turn back. Early this morning the crow perched on a fence rail and allowed the mockingbird to tease him by knocking into him again and again. The crow opened its black beak as if to snap at the mockingbird in a playful way each time they made contact. Just now, in the late afternoon, they flew together, all the way across the yard, then came to light in the grass, there to sit together for a few minutes before flying off in opposite directions. A cross species friendship? dkm