Just to chuck another sabot in the gears, there's a species of crow in England with strange markings which I see whenever we go to church. Their heads look grey at the back, but black at the front, as if they've been bobbing for worms in the inkwells at the nearby school; or perhaps they've got chalk-dusted by being hit from behind by an accurately-thrown board rubber while gossiping in class (as crows will).