A spiny soft-shell turtle reveals its gender. (Donald McKnight)

Imagine standing in a swamp in southeastern Oklahoma, up to your hips in muck. It’s humid and buggy, and a monotonous hum fills the air. But this buzz isn’t from insects or a moody rattlesnake.

It’s the sound of a shiny, seven-inch-long sex toy. Which you are currently applying to the genitals of a western chicken turtle. For science.

Curiously, this was the scene in the summer of 2014 as Donald McKnight, a herpetologist at Missouri State University, tested out a new, noninvasive method for figuring out whether turtles are male or female.

It might sound silly, but the reptiles can actually be pretty secretive about their sex. All of their relevant parts are hidden inside an orifice known as the cloaca, so scientists must rely on features like shell shape, tail size, claw length and eye color for sexing. The trouble is, these indicators are not always clear, and sometimes an individual turtle will have one feature that indicates “boy” and another that points toward “girl.”

Failing external cues, the scientists could then opt to measure the turtle’s testosterone levels by drawing blood or by performing a cloacoscopy, which basically means inserting a small telescoping camera into the cloaca. These methods are understandably stressful for the reptiles, time-consuming and difficult to perform in the field.

And that brings us to the vibrators.

You see, if you can catch a glimpse of a turtle’s penis, then you don’t have to bother with all those other clues. But it’s not as if the reptiles are just walking around waving the goods at passersby. No, they have to be romanced.

But we’re still learning what exactly turns turtles on. Earlier studies have revealed that common snapping turtles will evert their penises if you gently bounce them up and down. And Cotinga River toadhead turtles have been known to, uh, reveal themselves after their necks and limbs are immobilized. Scientists have also used a technique called electroejaculation on Yangtze soft-shell turtles; it uses electrodes to coax the animal toward erection and eventually ejaculation. The fruits of such labors are then used to try to create more of those critically endangered turtles through artificial insemination attempts.

But in his study, McKnight found that a little battery-powered stimulation was enough to make most male turtles evert their penises. This isn’t as easy as you might think, however. Some species, such as the spiny soft-shell turtles, responded quickly and robustly to any vibration on or around their tails, whereas other species, such as common musk turtles and Mississippi mud turtles, required a bit of foreplay first.

These species responded best to “moving the vibrator in slow, small circles on the abdominal and pectoral scutes,” or plates, McKnight wrote in a new paper on the method. (“Good vibrations: a novel method for sexing turtles” was published in the most recent issue of the journal Acta Herpetologica and included Hunter Howell, Ethan Hollender, and Day Ligon as co-authors).


A $10 sex toy helped scientists determine this western chicken turtle’s gender. (Donald McKnight)

In an interview, McKnight played down his talents. “It was really just a matter of moving the vibrator around and trying different techniques until I found ones to which the turtles responded well,” McKnight said.

Surely, no one will buck at the notion of finding new and better ways to study wildlife. But c’mon. Did it have to be a shiny silver vibrator?

“Since this was a pilot study, we bought the cheapest, most generic vibrator we could find,” said McKnight, adding that the apparatus was purchased online for about $10. “We did get a visit from the department’s secretary, who wanted to know why we were using our funding to order a vibrator.”

Needless to say, the mockery machine is starting to churn. McKnight said he’s already had someone call him “the vibrator guy” at a conference. Marc Abrahams, editor of the Annals of Improbable Research, said he is aware of the study and deemed it “clearly a worthy candidate for an Ig Nobel Prize.” (Previous Ig Nobel Prize winners include the scientists who discovered dogs tend to align their bodies on the North-South axis when they poop and those who found that nearly all mammals empty their bladders in 21 seconds.)

“I hope this won’t be my only lasting contribution to science, but I’m certainly proud to have it on my CV,” said McKnight.

David Steen, a wildlife ecologist at Auburn University (also known as “the guy who once gave a turtle CPR”), said these sorts of studies are valuable both for what they add to the scientific record, but also for the way they can bring the general public into the conversation.

“Talking about some of these innovative techniques can help raise attention to the fact that we still have a lot to learn about the imperiled creatures all around us,” said Steen, who broke the turtle vibrators story over at Motherboard.com.

That said, it’s important that we don’t all go out and start testing out personal massagers on wild reptiles.

“Although the research described in this study may be unconventional, it was done by professional biologists, for a good reason, and with all relevant permits,” said Steen, who confirms that he has never used any sex toys on turtles in either his personal or professional life. “Also, some turtles have serious bites that people should avoid.”

So what’s next for Team Turtle Vibrator? McKnight says that for the vibration method to be useful, it will require more testing in the field to nail down the best method for each species. He would also like to see someone test different styles of vibrator to see if some work better than others.

And for what it’s worth, he said he has no qualms about forging ahead with this line of inquiry, even if it becomes the butt of jokes.

“I think it is really important for people to occasionally see science and scientists like this. There is this stereotype that scientists are really rigid, awkward and detached from the society, and it’s just not true,” McKnight said. “We are normal people who just enjoy asking questions about the world around us and looking for answers to those questions. We enjoy jokes and comically absurd situations just as much as anyone else.”

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