  Many complex networks, including human societies, the Internet, the World
Wide Web and power grids, have surprising properties that allow vertices
(individuals, nodes, Web pages, etc.) to be in close contact and information to
be transferred quickly between them. Nothing is known of the emerging
properties of animal societies, but it would be expected that similar trends
would emerge from the topology of animal social networks. Despite its small
size (64 individuals), the Doubtful Sound community of bottlenose dolphins has
the same characteristics. The connectivity of individuals follows a complex
distribution that has a scale-free power-law distribution for large k. In
addition, the ability for two individuals to be in contact is unaffected by the
random removal of individuals. The removal of individuals with many links to
others does affect the length of the information path between two individuals,
but, unlike other scale-free networks, it does not fragment the cohesion of the
social network. These self-organizing phenomena allow the network to remain
united, even in the case of catastrophic death events.
