Dolphins are even more similar to people in their social behavior than before. This is written by an international research group around the biologist Stephanie King from the University of Bristol in the "Proceedings of the National Academy of Sciences". For a long time it was seen as a unique feature of human societies to form several levels of strategic alliances. The researchers now found that large pools (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 therefore not concerned with economic advantages or military operations - but only about access to females.
The scientists had previously examined the social networks of 121 male Indo-Pacific bottlenose dolphins in Shark Bay, 800 kilometres 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 alliance levels or "orders" in the competition for females: the first-order alliances between two or three males are about living together cooperatively with individual females. The second-order alliances include from 4 to a maximum of 14 unrelated males competing with other alliances for access to females. In the case of third-order alliances, whole groups of the second order cooperate with each other.
"Cooperation between allies is widespread in human societies and one of the characteristics of our success," explains Stephanie King. "Our ability to build strategic, cooperative relationships on several social levels, such as trade or military alliances- both nationally and internationally- was once considered unique for our species."
Such multi–level alliance networks would also be used by dolphins - and on a large scale. In addition, the study proved that bottlenose dolphins rely not only on size, but above all on the cooperation between the individual groups when it comes to spending more time with the females. This will ultimately increase reproductive success, says King.
So far, the efforts to understand human social evolution have almost exclusively limited comparisons with other primates, especially chimpanzees and pavia, the study continues. However, it is becoming increasingly clear that important knowledge could also be obtained by comparisons between people and distant related living things.
