Humpback sex photographed for first time – and both whales are male
A pair of humpback whales have been observed having sex for the first time by scientists – and both of them were male.
Exactly why male humpbacks engage in gay penetrative sex is “the million-dollar question”, researchers say.
The behaviour was observed by two photographers who were on a boat off the coast of the Hawaiian island of Maui.
The photographers, Brandi Romano and Lyle Krannichfeld, showed the images to Stephanie Stack, an expert from the Pacific Whale Foundation, which is based in Maui.
“They shared the photos with me for my opinion, and when I saw them, I was just stunned. Humpback whale copulation has never been seen or documented before anywhere in the world. So that’s a very special and amazing encounter,” she told National Geographic.
The behaviour was documented in a paper published by the journal Marine Mammal Science.
“Humpback whales are a species whose social behaviour has been studied for decades, but whose sexual behaviour remains largely undescribed,” the scientists said.
“Despite decades of research on humpback whales around the world, reports of penis extrusion by males are relatively rare. This is the first report of penetration by a humpback whale, and the first report of sexual activity between two male humpback whales.”
The two whales are part of a population that has been studied for more than 40 years. Scientists were able to identify them, and knew that they were both males. The fact that the penis of one of the whales was readily visible in the sexual encounter also led to no doubts about its gender.
The whales engaged in several copulating sessions, with each encounter lasting about two minutes.
Scientists have suggested several possible reasons for why two male humpbacks might have sex.
It could be that it is practice for future encounters with female whales. Or it could be a means by which one male establishes dominance over the other. It might be a way for the mammals to bond. Or it may be that one whale was giving comfort to the other.
That last theory is supported by the fact that one of the whales appeared to be in a poor state of health – it was emaciated, possibly owing to an injury to its jaw, which would have made feeding difficult. And it was seen to be carrying a high number of parasitic whale lice.
The precise reason for the gay sexual encounter was “the million-dollar question”, Stack said.
“Given how little we understand about humpback whale reproduction, and how much we’re still understanding about their social dynamics, I wouldn’t venture a guess as to exactly what motivated the behaviour.”
Same-sex activity has been observed previously in several species of marine mammal, including killer whales, grey whales, bowhead whales, walruses, seals and dolphins. “Homosexual behaviour is common in the animal kingdom,” the scientists wrote in their report. “Sexual interactions between individuals of the same sex have been documented for a wide range of species.”
The researchers said that “the purpose for non-reproductive behaviour is varied. Proposed functions include learning or practising reproductive behaviours, establishing or reinforcing dominance relationships, forming social alliances, and/or a reduction in social tension”.
Whale experts came across hints that male humpbacks might engage in sex with each other in 1998, when Professor Adam Pack, a researcher from the University of Hawaii, published an account of a male humpback with its penis visible swimming up to another male, which had died, and wrapping its pectoral fins around it.
“It seemed to be attempting either some type of dominance display, or maybe this was a signal for copulation, or an invitation. We didn’t know,” Pack said.