Dolphins are even more similar to humans in their social behavior than previously thought. This is what an international research group led by biologist Stephanie King from the University of Bristol writes in the Proceedings of the National Academy of Sciences. Forming multiple levels of strategic alliances has long been considered a unique feature of human societies. The researchers have now found that bottlenose dolphins (Tursiops aduncus) build very similar cooperative relationships on the Australian west coast. According to the study, the goals of the clever marine mammals differ significantly from those of humans: They are not concerned with economic advantages or military operations – but solely with access to females.
The scientists had previously examined the social networks of 121 male Indo-Pacific bottlenose dolphins in Shark Bay, 800 kilometers north of Perth. The amazing result: “All 121 males are directly or indirectly connected in social groups in the largest alliance network known outside of humans,” they write.
But not that unique?
Male dolphins form three levels of alliances or “orders” in the competition for females: First-order alliances between two or three males are about living cooperatively with individual females. The second-order alliances include 4 to a maximum of 14 unrelated males that compete with other alliances for access to females. In third-order alliances, whole second-order groups cooperate with each other.
“Cooperation between allies is widespread in human societies and one of the hallmarks of our success,” explains Stephanie King. “Our ability to form strategic, cooperative relationships at multiple social levels, such as trade or military alliances—both nationally and internationally—was once thought to be unique to our species.”