These are the 1st images of humpbacks having sex, and they’re both males

When biologist Stephanie Stack first saw the photographs of two humpback whales mating in the warm waters of Hawaii, she says her mind was “completely blown.”

“When I realized that it was two males, it was not what I was expecting,” she told As It Happens host Nil Köksal. “I thought, oh my gosh, this is incredible.”

Stack, chief biologist at the Pacific Whale Foundation in Maui, says this is the first time humpback whale sex has been documented. She co-authored a paper about the rare sighting in the journal Marine Mammal Science.

The findings are just the latest in a growing body of evidence that same-sex sexual interactions are widespread in the animal kingdom. 

But one researcher cautioned against making broad assumptions about humpbacks based on a single documented instance — especially because one of the whales appeared to be in poor health.

‘A bit sceptical at first’ 

The photos were taken in January 2022 just west of Maui. The two humpbacks approached a boat, then began mating a few metres beneath the vessel.

Lyle Krannichfeld and Brandi Romano, both professional photographers, happened to be there to capture the moment.

“I was contacted by these two photographers, and they told me that they had captured what they believed to be the first photographic evidence of two humpback whales mating,” Stack said. “I was a bit skeptical at first.”

But sure enough, the photo they sent showed two humpbacks mid-coitus, one clearly penetrating the other.

Then, she says, one of the photographers asked: “Are you sure that this is a male and a female?” So they pored through the entire series of photos to get a closer look. 

“We looked at the underside of the whales and realized, yes, indeed, these are two male whales,” she said

Same-sex encounters common among animals

Vincent Savolainen, a biologist at Imperial College London in the U.K. who was not involved in the study, called it “an important piece of research demonstrating the usefulness of the broader scientific community in capturing evidence of events rarely observed in the oceans.”

But it’s not, he said, surprising. 

Last year, Savolainen authored a study that showed more than 1,500 species of animals have displayed some degree of same-sex sexual behaviour, including fish, frogs, birds and primates.

Stack’s paper also notes that same-sex sexual behaviour has also been previously observed in orcas, walruses, seals, and several species of dolphins. 

“The biological underpinning and function of such behaviour remain largely unknown,” Savolainen told CBC in an email. “I hope this research will help destigmatize homosexuality and bisexuality and acknowledge sexual diversity in nature and society.”

Injury could be a factor

But humpback researcher Jackie Hildering cautioned against making widespread assumptions about these humpbacks — or humpbacks in general — based on a single observation.

Especially, she says, because the paper describes the penetrated whale as being emaciated with a visibly injured jaw, possibly from a collision with a vehicle, which could have impacted his ability to eat.

“You can’t make judgments about how two fully healthy male humpbacks would have interacted,” Hildering, communications director at Marine Education and Research Society in British Columbia, told CBC.

“Is it exploratory? Is it learning related to mating? And is it possibly also dominance?

“We know that the one whale would not have been in the state to choose for the interaction in a way that they normally would have been able to because they were so compromised in their condition.”

The study acknowledges the injury “may be relevant to the behaviour reported here.”

But whatever happened between the pair, Hildering says it’s not for people to pass judgment.

Any assumptions about these humpbacks, she says, say more about the people making them than the whales themselves — including the assumption early on that the pictured whales were of the opposite sex. 

“There is no good. There is no bad,” she said. “It’s just wild behaviour.”

Stack says there’s a lot about humpback whales that remains a mystery. Just last year, scientists published the first footage of a humpback giving birth.

“They breathe air, but they spend most of their lives under the water. And we, as the people studying them, do most of our research from boats or land,” she said.

“And so we just get these tiny glimpses of their lives, really.”