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Doubtful Sound's female bottlenose dolphins have learned not to be pushed around by their male counterparts, a study has discovered.
David Lusseau, a socio-ecologist at Dalhousie University in Halifax, discovered after two years of studying the population that the male dolphins allowed the females to choose their sexual partners, unlike many other dolphin species that coerce them into sex, Canadian website cnews.com reported.
"There's a greater choice for females to actually select their mates and the males have to compete by sticking close to these females," he said. His findings have since been published in the scientific journal PLoS ONE.
"It opens new avenues of thinking about the full extent of the benefits of having complex social relationships in males."
Dr Lusseau tracked the population of about 65 dolphins in Doubtful Sound from 1999 to 2001 .
He identified all 65 dolphins and could monitor their behaviour as they began their mating rituals.
He found that like other bottlenose dolphins, these ones fought among themselves to win over female partners, but unlike similar dolphins in Florida and Australia, they refrained from forcing the females to have sex.
The discovery led to a broader understanding of the species thought to have highly sophisticated social relationships similar to humans.
Dr Lusseau said this population differed greatly from other groupings because they formed alliances with other males but with no immediate, short-term benefit.
For example, male dolphins usually form coalitions with other dolphins because they need help in overpowering a sexual partner or fending off male rivals.
But in this case, there is no upfront benefit because they are not using other males to coerce females into having sex.
"The underlying implication is that there is some benefit to forming a group," he said.
"The long-term benefit might be the maintenance of a group of males and having that social cohesion."
- NZPA
