Flipper is a swinger: Scientists reveal secrets of dolphins’ bisexual society
By Ted Thornhill
PUBLISHED: 11:47, 28 March 2012 | UPDATED: 11:56, 28 March 2012
We’ve always known dolphins were clever – but now scientists have revealed that their societies are more complex than previously thought, with some of the animals even having bisexual and homosexual relationships.
Researchers from the University of Massachusetts Dartmouth studied 120 bottlenose dolphins in Shark Bay, Western Australia, and found they had incredibly intricate relationships.
Some of the males were found to nurture bisexual and even homosexual relationships.
Co-author Richard Connor told Discovery News: ‘I work on the male dolphins, and their social lives are very intense – it seems there is constant drama.
‘I have often thought, as I watched their complicated alliance relationships, that their social lives would be mentally and physically exhausting, and I’m glad I’m not a dolphin.’
His team found that there were several layers to dolphin society with some males bonding in twos or threes to herd females in the mating season, with others preferring to roam in gangs numbering between four and 14.
These groups are by no means casual arrangements with one seven-strong group still operating as a unit 17 years after they were first identified.
Dolphin groups, the researchers found, largely lived a peaceful existence and didn’t patrol boundaries of a defined area.
Both sexes are capable of aggression, though, according to Connor, ‘less frequent and more subtle’ with females and occasionally serious with males.
But he added that the males they don’t squabble constantly.
The results of the study will be published in Proceedings of the Royal Society B.
It follows research by the Wildlife Conservation Society that shows that dolphins’ lack of hostility towards other groups might be influenced by environmental factors.
It found that groups of dolphins in the western Indian Ocean do not mix freely with one another because populations are kept separate by currents and other unseen factors.
Specifically, the researchers have found that genetically distinct populations of the Indo-Pacific humpback dolphin may be formed in part by currents, surface temperature differences, and other environmental barriers, a finding made possible by using both genetic data from dolphins and environmental information from remote-sensing satellites.