Sharks are often viewed as solitary creatures, but new research reveals that sharks actually have rich networks and complex social lives.

Bull sharks cultivate a range of social relationships, from casual acquaintances to best friends  and they even avoid certain sharks – according to a study, from the University of Exeter, University of Lancaster, Fiji Shark Lab and Beqa Adventure Divers.

The new study is based on six years of observations of 184 bull sharks in three age categories: sub-adult (not yet sexually mature), adult, and advanced-adult (post-reproductive age).

Researchers examined both broad-scale interactions, like individuals remaining within one body length of each other, and small-scale interactions, like parallel swimming and lead following.

They found that both sexes preferred to socialise with female sharks, but male sharks had more connections on average than females. Male sharks are the smaller of the two sexes, so the female sharks may act as a buffer for conflict or aggression for the males.

“We are only just beginning to really understand the social lives of many shark species. Just like other animals, they likely gain benefits from being social – this may include learning new skills, finding food and potential mates while avoiding confrontations,” said professor Darren Croft, from Exeter’s Center for Research in Animal Behaviour.

The majority of sharks in the “core” of the social network were adults, at sexual maturity and those that are not yet sexually mature were generally less connected.

The risk of predation, from adult bull sharks, means youngsters often stay separate from the social groups, although some bolder individuals make social ties and learn from the older sharks.

“These older individuals have many years of experience honing their skill sets, hunting and mating, and sociality may not be as integral to their survival as it is for an individual in their prime,” said the study’s lead author Natasha Marosi.

Marosi also emphasised the importance of developing a deeper understanding of sociality within shark species, which she believes can help inform policy frameworks for their management and preservation.  

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