Young male dolphins cultivate ‘wingmen’ that help them find a mate in later life, while females focus on honing their fishing skills for motherhood, a study has found.
US researchers studied records of dolphin activity in Western Australia’s Shark Bay spanning some 30 years, looking at the groupings youngsters formed.
The team found that dolphins under the age of 10 spend their time on different activities in order to best prepare themselves for their adulthood.
At the age of around three to four years, dolphins leave the protection of their mothers’ sides to venture out in the world — at which point they start living in ever-changing groups, or ‘pods’, that come together and reform in different combinations.
Experts found that of the 1,700-odd bottlenose dolphins that have been monitored in Shark Bay since the 1980s, those aged 10 and under flit from pod to pod as often as every 10 minutes — but typically spend the most time with a few ‘close friends’.
The team said that this camaraderie was not a product of just happening to live in the same area and having, as a result, more frequent interactions with each other.
‘These relationships reflect true preferences,’ said paper author and biologist Allison Galezo of Duke University in Durham, North Carolina.
Ms Galezo and colleagues found that male dolphins prefer to hang out with other males, while females also favoured their own company — however, the interactions varied depending on the specific sex involved.
Male dolphins were seen to spend more of their time together — either resting or engaging in friendly contact like rubbing their flippers, swimming close together and mirroring each other’s movements.
In contrast, the female dolphins were seen to socialise less — instead spending twice as much time foraging for fish in comparison with their male counterparts.
According to Ms Galezo, the differences in behaviour of the young dolphins may be related to the different demands they will go on to face later in life.
‘The juvenile period can be an opportunity to develop social skills that will be important in adulthood, without the high-stakes risks that go with sexual maturity,” she explained.
Adult male dolphins in Shark Bay, for example, form pairs or gangs of threes to join forces, isolate fertile females and coerce them into mating.
Because of this, having experience of building social bonds as a youth may be vital to ensuring that they have an opportunity to pass on their genes.
For female dolphins, however, success as an adult depends on being able to take in enough calories daily to keep nursing each calf for up to three years — perhaps explaining why young females focus their time on practising foraging for fish.
The full findings of the study were published in the journal Behavioral Ecology.