Sharks are often seen as solitary and dangerous animals that roam the ocean alone. But new research is challenging that image.
A long-term study of bull sharks in Fiji has found that these animals actually form social relationships and even choose specific companions, much like humans do.
The study was carried out at the Shark Reef Marine Reserve in Fiji by researchers from the University of Exeter, the University of Lancaster, Fiji Shark Lab, and Beqa Adventure Divers.
Over six years, the team closely observed 184 bull sharks of different ages, including younger sharks, fully grown adults, and older individuals.
The researchers discovered that bull sharks do not simply mix randomly in the water. Instead, they show clear social preferences, choosing certain sharks to spend time with while avoiding others.
According to lead researcher Natasha Marosi, this behavior is similar to how humans build social circles, with some individuals becoming close companions and others remaining distant.
To understand these relationships, scientists studied how often sharks stayed close to each other, as well as how they moved together. They looked at behaviors such as swimming side by side or one shark following another. These patterns helped them map out social connections within the group.
The results showed that adult sharks were the most socially active. They formed the core of the social network and were more likely to interact with other sharks, especially those of a similar size. In contrast, younger and older sharks tended to be less connected.
Interestingly, both male and female sharks preferred to interact with females. However, male sharks generally had more social connections overall. One possible reason is that males are smaller than females, so staying socially connected may help them avoid aggression from larger individuals.
The study also found that older sharks, which have already gained experience in hunting and mating, seem to rely less on social interactions. Younger sharks, on the other hand, are more cautious. Many of them stay in safer, near-shore areas or rivers to avoid predators, including adult sharks. Only a few bold younger sharks venture into the reserve, where they sometimes form connections with older individuals.
These relationships may offer important benefits. By socializing, sharks could learn new skills, find food more easily, and identify potential mates. Social connections may also help reduce conflict and increase survival chances.
The research site in Fiji provided a rare opportunity for scientists to observe the same sharks over many years. This allowed them to track how relationships change as sharks grow and age. It is one of the most detailed studies ever conducted on shark social behavior.
Overall, the findings suggest that bull sharks have more complex social lives than previously believed. Understanding these social patterns is not only important for science but also for conservation. By learning how sharks interact and depend on each other, researchers and policymakers can develop better strategies to protect these animals.
This study reminds us that even creatures we often misunderstand can have rich and surprising social worlds beneath the surface.
