Venomous sea snakes are trying to have sex with scuba divers, study says

Researchers in Australia have found that large, venomous sea snakes known to approach scuba divers might not be looking to harm humans.

Instead, they’re probably interested in mating.  

Aipysurus laevis, known as olive sea snakes, who swim toward divers could be experiencing “misdirected courtship responses,” according to a study published this week in the journal Scientific Reports.  

Rick Shine, a professor at Macquarie University in Sydney, and his co-authors found that instances of the snakes approaching divers was most common during the species' breeding season between May and August. And most of the snakes who approached humans were males. 

Some of the male animals in the study also "made repeated approaches, spent more time with the diver, and exhibited behaviors (such as coiling around a limb) also seen during courtship." 

Shine explained to USA TODAY that male snakes often made their move after losing “contact" with a female snake or competing with another male. 

"This is a very fundamental question: Why are the snakes doing something that, at first sight, seems really stupid?" Shine said. 

"They can't eat a person. The person isn't a threat. Why are they attacking them? And of course they're not attacking at all. They're just looking for a bit of romance," he said. 

Crab-tivating:Chemical in plastic arousing hermit crabs

Watch:Giant snake slithers out of Sydney supermarket spice aisle

Shine added that the snakes who approach divers are trying to learn more about their target and that the interaction is "really a story that’s all about mistaken identity." 

"It sort of sounds a bit silly that a male could mistake a human being for a female snake, but the reality is that snakes are a bit like dogs," he said. "They rely on scent rather than vision."

Female olive sea snakes can grow to approximately 6 feet, according to the study. Male snakes of the species are typically smaller. 

The snakes are venomous, but they are rarely aggressive enough to bite humans while underwater, Shine said. 

"These things are deadly. They're highly venomous," Shine said. "But if you just hang there in the water and wait for it to check you out, it'll rapidly work out that you're not interesting and it'll go away."   

The research is based on data collected from 1994 and 1995 by Tim Lynch, a co-author of the study. Lynch's data  includes 158 interactions with sea snakes over 250 hours off the northeastern coast of Australia.  

Kate Sanders, an evolutionary scientist at the University of Adelaide and co-chair of the International Union For Conservation of Nature’s Sea Snake Specialist Group, who was not involved in the research, told The New York Times: “I’ve always expected that the motivation for this behavior is sex.”

“I don’t know how you would say it other than the snakes have got their beer goggles on,” she said. “Their hormones are skewing their behavior.”