By Tui Benjamin
Randy male dolphins offer females brightly-coloured gifts in their attempts to find a mate – and even enlist WINGMEN pals to help them.
Boffins made the fascinating discovery after witnessing Australian humpback dolphins pick up and present sea sponges to would-be partners in a rare sexual display.
They released incredible footage of the phenomenon – the first time the behaviour has ever been caught on camera – after spending 10 years following the animals across the coasts of North Western Australia.
It is believed dolphins do this to show their strength and quality as a mating partner, with some large males even seen working together in pairs in their attempts to attract a female.
Lead author Dr Simon Allen, from the University of Western Australia’s School of Biological Science, said: “We were at first perplexed to witness these intriguing behavioural displays by male humpback dolphins.
“But as we undertook successive field trips over the years, the evidence mounted.
“Here we have some of the most socially-complex animals on the planet using sponges not as a foraging tool, but as a gift.
“Gift-giving is extremely rare among non-human mammals.
“Humans do it – we present roses and gifts to a chosen partner to try and convince them that we’re a suitable mate – and this might be what’s going on in the humpback dolphins.
“It could be a display of the male’s quality, or perhaps even as a threat in the behavioural contexts of socialising and mating.”
Co-author Dr Stephanie King added: “The formation of alliances between adult male animals for the purposes of coercing females is uncommon, since mating success cannot be shared.
“This is a new finding for the species and presents an exciting avenue for our future research.”
In one instance, a male dolphin was spotted diving down to remove a large marine sponge from the ocean floor before balancing it on his back and pushing it towards the female.
The humpback dolphins were also filmed performing visual and acoustic displays to assert themselves to would-be female partners.
Experts say the use of objects in sexual displays by non-human mammals is extremely rare and suggests dolphins could be far more socially-complex than we previously thought.
The scientists now plan to investigate whether presenting the sponges actually improves the dolphins’ chances of mating.
Dr Allen added: “Never was this in a foraging context, certainly at least for the males, it was always in the context of approaching an adult female that has a calf of weaning age and is therefore ready to be mated with.
“One of the pleasing elements of this research is it highlights to us that there’s another species out there that is quite socially complex, more socially complex than we had previously recognised.
“Also they engage in these complex behaviours – they are problem solvers, they are thinking animals. And these complex communities of animals are living there just off our coastlines, just beneath the waves.”
The research, conducted in partnership with the University of Zurich and Murdoch University, has just been published in journal Scientific Reports.