I've had roosters now going on nine years, and this is something I've never seen before. In fact, I believe it's something my present rooster has just started doing. When doing the sideways dance near a hen while dropping the wing, he strums that wing with his foot, making a mild thunder sound. Has anyone observed this in their roosters? I am wondering if this is normal in domestic roosters or perhaps my Cream Legbar rooster has learned it by being in proximity to wild turkeys that they sometimes mingle with. The tom turkey will display to his hens, feathers arrayed, then while moving a few feet forward, he will lower his wing, dragging the feathers across the ground making the sound my rooster is making by strumming his wing feathers with his foot. It sounds a lot like thunder, curiously. Sorry, I do not have a smart phone to video the action.