Metch & Ebbie... ever see (one of) the mating ritual(s) of ravens? The female sits on the ground or in the top of a tree. The male dives from thirty or so feet above her, swoops very close and climbs again as fast as possible. This is repeated many times until she accepts. I assume it's meant to show physical prowess, perhaps in defense of the nest, perhaps in hunting (yes, for those who think they are only scavengers, they do hunt mice, snakes, etc).