A study from researchers at the The University of Western Australia (UWA), University of Bristol, University of New South Wales and University of Massachusetts, found that a group of 121 male dolphins in Shark Bay, north of Perth, form alliances in order to mate with females.
Groups of dolphins also appeared to have rivalries with others.
Dolphins are incredibly intelligent animals. Scientists have previously found evidence of them being quick learners, and that they are able to problem solve. Research has also shown they form complex, social bonds with each other.
While they are not the only species to do this, scientists are finding more and more evidence that they share several key characteristics with humans.
“A number of animals form alliances or otherwise ’team up,’ usually in contests over rank within a group or access to females—think of lions, for example, which typically ally with relatives and once mature, attempt to overthrow an established alliance in order to take over a pride of females,” research co-author Simon Allen, an Adjunct Research Fellow at UWA and UWA Oceans Institute, told Newsweek.
“Certain primates form coalitions and alliances in rank related contests, and this too is usually over access to mating rights. Male dolphins in Shark Bay, on the other hand, form alliances within a large, open, social network.
“We show that this is the largest alliance network known outside of humans, and that these alliances are not only strategic but multi-level.”
Other co-authors on the report were Stephanie King, an Adjunct Research Fellow from UWA’s School of Biological Sciences and UWA Oceans Institute, Richard C. Connor of Florida International University and Michael Krützen of the University of Zurich. Findings are published in PNAS.
The team noticed there were several types of alliance formed between the dolphins.
There were first order alliances, which allowed males to capture female dolphins for hours or weeks. Then there were second and third order alliances, where dolphins would steal females from other groups, and defend themselves against “theft attempts.”
The study found that males with stronger third alliance bonds were able to protect females for a longer period of time.
“[This] supports an earlier conjecture we made for the reason males have intergroup alliances. Second-order alliances vary in size from four to 14 and [individual] members may be widely scattered in an area,” Allen said. “If you are a trio alone with your female, third-order allies may be important backup [in the event you and your buddies are attacked by another alliance for your female].”
Scientists also found that these alliances were integral to the dolphins’ reproductive success.
“Strategic, multi-level alliance formation was once thought unique to humans, say local football team, provincial team and then national team, or local council, state government and even international alliances—this level of cooperation is a hallmark of our intelligence and success as a species,” Allen said. “Here we see a remarkable three levels of alliance formation in a population of a species other than our own.”
Allan said this further shows that dolphins share several similarities with humans. Other than forming alliances, dolphins each have a unique whistle which is the equivalent of the human name. They also have “extremely large brains, three times larger than similar-sized relatives.”
Scientists undertook the research by analysing the dolphins behavior over decades.
During this time, Allen said scientists have built “an incredibly rich and detailed picture of the population’s social lives.”
“[We researched] who are friends, who are foes and how does this change over time? Specifically, we analyzed association and consortship data to model the alliance network,” he said.
Update 8/31/22 10.45 a.m ET: This article was updated to mention co-authors Richard C. Connor and Michael Krützen of the University of Zurich.
