They are clearly marked social structures. They are formed by male bottlenose dolphins. And it is the largest known network of multilevel alliances outside humans. The University of Bristol (UK) proved it. These cooperative relationships between groups increase male access to a contested resource. Dolphins form huge alliances to gain access to females.
Strategic alliances
Indo-Pacific dolphins were studied in Shark Bay, Western Australia. They form first-order alliances of two or three males. They cooperate in foraging consortia with individual females. Second-order alliances are formed between four and 14 unrelated males. They compete with other alliances for access to females. And third-order alliances occur between cooperating second-order alliances.
Dr. Stephanie King, co-author of the study, explains, “Cooperation among allies is widespread in human societies. It was thought to be unique to our species,” she adds.
“Male bottlenose dolphins form the largest known multilevel alliance network outside of humans. Cooperative relationships between groups allow males to spend more time with females. They thus increase their reproductive success.” Social bonds between alliances provide males with long-term benefits.
Not only in humans
Intergroup cooperation in humans was thought to be unique. But intergroup alliances can arise in other species. The publication of the importance of intergroup alliances in dolphins in 2022 has special significance. The team is celebrating the 40th anniversary of the start of research on Shark Bay dolphins in 1982.
Dr. Michael Krützen is another author of the study. He is director of the Institute of Anthropology at the University of Zurich. “Dolphins form huge alliances. These are characteristics that were previously considered exclusively human. It demonstrates highly social taxa and great brain capacity.”
