Magpies often have the most odd behaviour - perhaps because they're so visible?
Several times (about three, really ...) I've seen a gang of magpies on a flat roof nearby with two of them wrestling (if you can do that without arms?) while the rest of the gang sit around in a circle either cheering on the contestants or making bets? This isn't a brief phenomenon - I've seen the fight go on for 10-15 mins ....
