The Secret to Dolphin Seduction Is the Gift of a Large Marine Sponge

In the absence of the finicky art of seduction, there would be no need to dip strawberries in chocolate. The heart-shaped jacuzzi industry would dry up, the artificial rose petal market would wither, and gas-station Valentine’s Day card companies would fold. But what if we’re just doing it wrong? Somewhere an Australian humpback dolphin is shaking his head, and wondering when we’re going to come to our senses. Because, in dolphin seduction, the sponge is king. Everybody loves the sponge.

For the past decade, scientists from University of Western Australia, the University of Zurich, and Murdoch University have been observing dolphin mating behavior off the northwest coast of Australia, and they recently published a report of this gifting practice in the journal Scientific Reports. It goes like this: A male dolphin finds an appealing female. He then dives deep to the bottom. Next he locates a large marine sponge, and balances it precariously on his rostrum. Finally, he tosses it toward his sponge-worthy queen.

The sponge is a present, yes, but researchers believe that it may also be a test of the male’s valor, strength, and quality as a mate. Choosing the right sponge and successfully extricating it from whatever hard thing it was attached to could be a sign of dexterity and strength. On top of that, finding and presenting the sponge “may also represent a symbol of cognitive ability,” they report, because not just any numbskull can find a sponge that good. What’s more, it is a risky operation that exposes the male to the risk of shark attacks. He’s not just strong, capable, and smart, ladies, he’s brave, too. “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 behavioral contexts of socializing and mating,” said Simon Allen, the lead author of the study, in a statement.

Researchers say that, as gifts, sponges aren’t interchangeable with the other objects dolphins like to play with—seagrass, sea cucumbers, branches, rocks, shells, coral, bits of trash. It’s a sponge or nothing. Dolphins have a variety of uses for the invertebrates, including using them as protection (not like that, get your mind out of the gutter) from sharp objects as they root around for food on the seafloor. But they might also just be tchotchkes—proof of love and worth. Embroidered teddy bears would probably mean more if you had to risk a shark attack to get one.