OK, I spend my time studying and writing about leadership. Someday you come across video like this that puts all of that into question. This bird behavior, like much swarming, requires no leaders; all that is necessary is that each individual know what to do in relation to its immediate neighbors. Understanding swarming is one reason that I have come to see leadership as a process, not a position and that a fundamental goal of the leadership process is to facilitate self-organization.
Watch and enjoy. The fun starts about :30 in.