Much Like Humans, Dolphin Pods Have Complex Social Structures

These marine mammals are known for building unique cultures within their social groups.

By Lily Carey
May 8, 2024 3:00 PM
Pod of common dolphins in Algoa Bay, Port Elizabeth
(Credit: lennjo/Getty Images)

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Dolphins are known by many for their playful nature and remarkable intelligence. But experts say they have far more in common with humans than meets the eye — like the fact that they’ve been known to form highly advanced social dynamics, building friendships and relationships much like we do.  

Dolphins typically live in groups called pods, which can consist of as few as two dolphins or as many as 1,000 dolphins in a “super-pod”. Most pods include somewhere between 40 and 60 dolphins, and this group dynamic gives dolphins a major advantage in hunting prey and hiding from predators.   

Within these pods, dolphins do more than just mate. Often, they develop complex social relationships with each other. They’re also known to have unique individual personalities, just like humans. And the social dynamics and distinctive culture that exists within a pod can have major impacts on how dolphins in that pod interact with each other, and with their surroundings. 

“The social aspect is such an important one to understand to be able to protect their populations, because it affects their ecology and how they live in the environment,” says Cindy Elliser, a marine mammalogist who leads the nonprofit group Pacific Mammal Research. “Those cultural losses can be huge.” 

A ‘Fission-Fusion’ Society 

Experts say a pod isn’t simply just a group of dolphins; within that group, dolphins form both short-term and long-term relationships, much like humans do. 

In such fission-fusion societies — a type of social dynamic that exists in many other animals, such as chimpanzees — individuals often spend most of their day rotating between different groups. Throughout this rotation, though, they also maintain lifelong bonds with a few individuals in the system. As researchers from the Shark Bay Dolphin Project put it, “each animal has certain individuals he or she prefers to associate with.” 

According to Elliser, this fission-fusion dynamic is one of the many social habits that dolphins share with humans.  

“If you think about your daily life, you wake up and you're with your family in the morning, and then you go to work, and maybe you go out to lunch with some other friends… and then that cycle repeats,” Elliser says. “You're moving in and out of groups throughout the day, and the groups are kind of changing, but you still have these long term relationships that can last for your entire life.”   


Read More: Just How Intelligent Are Dolphins?


Group Living Has Benefits — and Drawbacks 

From her research, Elliser says she’s seen dolphins develop a unique social culture within their pods. They’re highly social animals, and navigating the ocean with a large group of other dolphins can be important, both psychologically and for survival.  

The pressures that come with group living, however, can also shape the dynamics of a given pod.  

“The main thing is the fight for resources,” Elliser says. “The bigger the group, the more you have to share the resources that are available.” 

Elliser, who also serves as a research associate with the Wild Dolphin Project, saw these pressures firsthand while conducting a study on how dolphins assimilate into new pods, published in Marine Mammal Science in 2013.

For that study, scientists from the Wild Dolphin Project followed a group of about 50 dolphins from Little Bahama Bank who had lost nearly 40% of their population after two devastating hurricanes in 2004. This large group then “immigrated” into another pod based in Great Bahama Bank, and the two populations adjusted to this shared living dynamic over the course of several years. 


Read More: Here's Why Dolphins Have to Shout Underwater


Migration Patterns and Dolphin Behavior

Today, the two dolphin pods are essentially living as one. But, just like with humans, dolphin immigration can introduce a whole new set of individuals and social dynamics into a given environment, says Elliser, bringing changes and challenges. The competition for resources was one of the main impacts researchers noticed, as dolphins from the new population ended up traveling north to hunt prey and avoid competition with the resident population. 

Other studies by Wild Dolphin Project researchers have found that dolphin immigration can lead to increased aggression in some places, spurred by overlapping ranges.  

“In coming together, trying to find resources, you kind of have to break up and split apart, or fight for the one resource that there is,” Elliser says. 


Read More: Bottlenose Dolphins Form Alliances Similar To Humans


How Personalities Impact Dolphin Behavior

Males and females in many species have been known to take on different responsibilities in their families and social orders. In recent years, though, experts have split on the role that sex plays in dolphins’ social dynamics.   

Some scientists have found evidence that personality actually has a greater impact on dolphin sociality than sex. Dolphins are known for having strong individual personalities, too: A 2020 study by the Bottlenose Dolphin Research Institute found that dolphins with bold, curious dispositions often played a more central role in their social systems than those who were more shy — regardless of their sex.  

According to the results of the study, which tracked a pod of wild bottlenose dolphins in the Mediterranean Sea over the course of nine years, those bolder dolphins often had a greater role in spreading information to others. And individuals varied widely in their neophilia, or response to new figures and ideas. 


Read More: How Do Dolphins Choose Their Name?


Male-Female Dynamics in Dolphin Pods

Other studies have found that dolphin pods almost always include both males and females. Within these pods, though, there have been mixed results as to what roles males and females play. Elliser and her team found that, in the two pods of dolphins in Great Bahama Bank, males often played the role of “social connectors”, forming bonds between the newcomer pod and the initial residents.  

“It’s pretty standard within other mammalian studies, where females kind of hang out and males are the ones that rove around. So this was just particularly interesting in that the males seem to be more connecting,” she says, adding that some male dolphins in this group also formed male alliances, or close lifelong best friends, Elliser says.  

Still, other researchers in other parts of the world haven’t found evidence of male alliances among dolphins. And because the “competition for resources” within dolphin pods can also involve males competing to mate with females, Elliser says her team is always looking to dig deeper into this area.  


Read More: The Unique Relationship Between Whales and Dolphins


Supporting Dolphin Populations

Amid the growing impacts of climate change, Elliser says studying dolphin social habits and immigration patterns could become crucial for conservation efforts.  

Much like the 2004 hurricane that sparked the documentation in her team’s 2013 study, global warming could lead to more frequent, more severe natural disasters that cause dolphin pods to split up and adjust their ranges. Increasing human traffic in dolphin habitats could also lead to similar immigration patterns.  

Conservation efforts are already underway globally to help dolphin populations continue to thrive. But recent studies have shown that insights on dolphin sociality can be central in designing policies and protections. Dolphin pods behave differently in different parts of the world, which means dolphin conservation isn’t a one-size-fits-all project.  

“We can protect (a certain) area, but if that's not biologically meaningful for (dolphins), it may or may not do what we want it to do,” she says. “And we can only do biologically meaningful things if we understand their population, and that includes the social aspects of their behavior.”   


Read More: Yes, Animals Create Culture and Pass It Along for Survival


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