Humpback whales photographed having sex — and gay sex — for the first time

Photographers have captured two male humpback whales having sex, in what experts say is the first time the species has been documented exhibiting sexual activity of any kind.

The social behavior of humpback whales has been studied and chronicled for decades. But in a study released this week in the journal Marine Mammal Science, the authors said they’ve produced the first photographs of this species having penetrative sex. 

The report’s three authors are marine biologist Stephanie Stack and the two photographers who captured the encounter, Lyle Krannichfeld and Brandi Romano, in waters west of the Hawaiian island of Maui in January 2022.

“We realized pretty quickly that there was a scientific significance to it,” Krannichfeld, 44, said. “Even if there were no articles published or nothing ever came of it, we knew that it was important to the scientific community and those who were studying the whales just because of the unique behavior.”

The encounter occurred between one male whale who appeared unhealthy or injured and a strong and healthy male whale, the report stated. The whale that received penetration was visibly emaciated and covered in whale lice that can proliferate on humpback whales that have lost mobility, the report said. 

The authors suggested the emaciated whale may have approached the photographers’ friend’s boat to seek cover from the other whale. Krannichfeld stressed that he and his friends did not approach the whales by boat or get out and swim with them once they approached, both of which are illegal.

After circling the boat and attempting to swim away from the healthier whale, the emaciated whale eventually succumbed, the report said. The healthier whale then held the other whale in place with its pectoral fins and began to penetrate the other whale. 

The authors said that the whales were observed for approximately 30 minutes and that the encounter took place roughly 15 feet below the surface. They added that whether same-sex behavior between two healthy male humpback whales would occur remains unknown.

When the photographers returned home and looked at the photographs they had taken, Krannichfeld said, they immediately knew they captured “a once-in-a-lifetime encounter.”

“The whales are a big part of our lives here in Maui,” he said. “Everybody that’s involved with them and who photographs them kind of realizes that that’s never been captured. Mating and birth are the two main things that are still kind of unknown.”

Shortly afterward, Krannichfeld and Romano shared the photographs with Stack, who identified both whales as male.

Krannichfeld, who owns a photography gallery in Maui, said sharing the photographs with the scientific community was “an honor.”

“I’m constantly taking photos of the whales and essentially making a product off of them,” Krannichfeld said. “So it’s nice to be able to feel like I’m giving something back to the whales, help people understand them better.”

Same-sex behavior is common in the animal kingdom and has been well documented in other species. The study noted that it has previously been observed in a number of marine mammals, including walruses, Amazon river dolphins and gray seals. 

Perhaps no other species has gained such widespread attention for its same-sex behavior as penguins. Over the last several years, gay penguin couples in zoos in Denmark, the Netherlands and the United States have gone viral for taking care of eggs and raising baby penguins together.

This story first appeared on NBCNews.com. More from NBC News:

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