The game is the same whether you live on the ground or beneath the waves. A decade-long study has found that male dolphins employ complex pick-up strategies, including offering gifts and rallying wingmen.

Perplexing behavior

The complex social behavior of dolphins never ceases to amaze me. They hang out in cliques, they remember their friends even after decades apart, and are often more humane than we are. But being really smart doesn’t really prevent you from looking like a complete fool when you’re in love, it turns out.

In a study recently published in Scientific Reports, Australian and Swiss scientists report that male Australian humpback dolphins, Sousa sahulensis, go the extra mile when it comes to impressing the opposite sex. Specifically, they offer females gifts (large marine sponges, to be precise), carry out elaborate visual and acoustic displays, and rally wingmen to help their case.

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“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,” said lead author Dr. Simon Allen from UWA’s School of Biological Sciences. “Here we have some of the most socially complex animals on the planet using sponges, not as a foraging tool, but as a gift, a display of his quality, or perhaps even as a threat in the behavioural contexts of socialising and mating.”

Underwater gifts

Researchers speculate that dolphins form temporary or permanent alliances, serving as wingmen for each other. They also act in seemingly silly ways, like carrying out the rooster strut, Allen says.

“The behavioral posturing by male Sousa is similar to that exhibited by bottlenose dolphins engaged in sexual displays in Shark Bay. The ‘rooster strut,’ for example, is performed by individual males or simultaneously by pairs of male in Shake Bay, where the head is arched above the surface and bobbed up and down, usually in the presence of a female.”

But the gift giving is even more impressive. Dolphins would dive to the seafloor and pluck large sea sponges, balancing them on the nose, presumably in a display of strength and agility — presenting themselves as suitable mates.

This type of strategy is rare in the non-human world but has been observed (to some extent) in other species. Male bowerbirds, for instance, toss colorful objects in the air to attract the attention of mates. But this is the first time dolphins or any other marine species has been observed to do so. It seems that study after study shows just how much we have in common with these intelligent creatures.

“This is a new finding for this species, and presents an exciting avenue for future research, Allen concludes.”

Journal Reference: S. J. Allen, S. L. King, M. Krützen & A. M. Brown. Multi-modal sexual displays in Australian humpback dolphins. doi:10.1038/s41598-017-13898-9