In Laguna, Brazil, a group of bottlenose dolphins ( Tursiops truncatus ) helps local fishermen and shows them where the schools of fish are. A study published in the journal Biology Letters analyzes the social behavior of these animals and offers clues to understand why this cooperation between man and dolphins has been maintained over time.
When dolphins find a school of fish, they warn their fellow humans by banging their heads or tails against the waves. At that moment, the sinners release their nets and thus manage to catch dozens of fish. In this corner of Brazil, men and dolphins have fished together for generations, but it is not yet clear the real benefit that the latter obtain or why only a third of the more than 50 dolphins that inhabit the lagoon are engaged in these activities.
To clear up the mystery, an international team of researchers has analyzed the behavior of these animals through individual photo identification and has observed that some individuals tend to bond stronger with their peers . It is precisely these dolphins that participate in cooperative tasks with men, and also these animals usually form independent groups from those that do not lend themselves to fishing in company.
Just as mothers teach their children some customs or behaviors, it seems that dolphins also teach each other, and that the pups in turn imitate the behavior of their elders.
“This is an interesting discovery,” explains Vicent Janik, an animal behavior researcher at the University of St. Andrews (UK). “Although genetics could influence this behavior, so that there are individuals more likely than others to cooperate, social learning seems to play a key role,” he explains.
In addition, this alliance between men and dolphins is the guarantee for their conservation in this area of Brazil, according to Fábian Daura-Jorge, one of the authors of the study. “If the fishermen lose the dolphins, they will lose their traditional way of life.”
