Male dolphins form the largest known social structures and alliances other than humans, an international team led by researchers from the University of Bristol, UK has shown.
These cooperative relationships between groups increase dolphin access to resources.
The scientists, together with colleagues from the University of Zurich, Switzerland, and the University of Massachusetts, USA analyzed the data to determine the structure of alliances among 121 adult males.
The success of dolphins depends on the ability to cooperate
Co-lead author Dr Stephanie King, Associate Professor at Bristol’s School of Biological Sciences, said: “Cooperation between allies is widespread in human society and one of the hallmarks of our success. Our ability to build 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.”
“Cooperative relationships between groups, rather than alliance size, allow males to spend more time with females, thereby increasing their reproductive success,” says Dr Simon Allen.
Understanding dolphins helps us understand our own evolution
Intergroup cooperation in humans was thought to be unique and distinguishes humans from our common ancestor with chimpanzees. “However, our results show that intergroup alliances can also occur in a social and mating system that is more similar to that of chimpanzees than that of humans,” said Richard Connor, a professor at the University of Massachusetts.
Professor Dr. Michael Krützen, study author and head of the Institute of Anthropology at the University of Zurich, said: “It is rare for non-primate research to be carried out by an anthropology department, but our study shows that important information about the evolution of characteristics previously thought to be uniquely human can be obtained by examining other highly social animals.”
Dr. King, cited by PHYSconcluded: “Our work highlights that dolphin society, as well as that of non-human primates, represent valuable systems for understanding the social and cognitive evolution of humans.”