Wet and wild
Scientists: Sea turtles have racing libidos
By VIRGINIA SMITH
Staff Writer
Last update: 26 June 2004
In the annals of the Chelonian Research Institute in Oviedo is a photograph that, Peter C.H. Pritchard says, proves that female sea turtles "like it."
"You see here," said the famed turtle expert, pointing at an azure seascape with two green turtles in flagrante delicto, "the female is at the bottom -- her flippers are free. Look what she's doing -- hanging onto his head!"
Sure enough, she was. Whether it was to keep him firmly in place, as Pritchard believes, or to headlock and hurl him back where he came from, may never be known.
Such are the mysteries of sea turtle sex.
While there is enough data on sea turtle nesting habits to fill a warehouse or two, sea turtle mating habits are another story. Though turtles tend to mate close to their nesting beaches, biologists who've seen hundreds of female turtles nesting, and thousands of babies emerging, seldom witness "the act" itself.
In area waters, the loggerheads have been at it like rabbits since spring, but "the only way for someone to really see it is to spend time within a mile offshore all summer long," said Jane Provancha, a biologist with Dynamac Corp. in Melbourne. (Provancha, in her 22 years studying marine turtles, has yet to catch them copulating.)
Yet while formal studies of sea turtle sex are scant, gossip and anecdotes abound among scientists: Leatherbacks like foreplay. Female greens are promiscuous. Male loggerheads mount scuba divers, and each other.
And year after year, the accounts increase, creating a patchwork of knowledge about sea turtle sex that, if not exactly comprehensive, at least confirms that they do "like it."
A lot.
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"Male sea turtles are hornier than hell," said John Musick, a biologist at the Virginia Institute of Marine Science. In the height of the breeding season (about a month before females come ashore) they will mount "just about anything," he said.
Pritchard said fishermen worldwide have long figured this out, and have historically used decoys to catch male sea turtles.
Any object "that's broadly oval and moving through the water" will do the trick, he said, holding a carved-wood "female" that looked more like a UFO.
Of course, other male turtles are also broadly oval and moving through the water. And if they're already hooked up with a female, all the better -- the second male will just pile on, sometimes nipping and slashing at the male below him. Leaving the female to cart around the whole ornery threesome, which can weigh well upward of a thousand pounds.
Pritchard had a photograph of that, too: a stack of green turtles, somewhere off the coast of Australia. The female would have a hard time surfacing to breathe, he explained, because of all the weight, and with the males' flippers occupied in securing her, she'd be the only one able to swim. After many such matings, her shell might be scarred to the bone from their claws.
But is she liking it? Who's to say?
A scuba diver in the Keys definitely did not like it when he was mounted by a male loggerhead in the mid-1990s, said Sue Schaf, administrator of the Turtle Hospital in Marathon. "Believe me," she said, "when male turtles are horny it doesn't matter."
She felt sorry for the victim of the attempted rape, who was not only shaken up by the experience but mocked publicly afterward. "It became quite the joke," Schaf said. "A lot of people for Halloween dressed like scuba divers with stuffed turtles mounted on their backs."
Much of the hard data on sea turtle sex comes from the Cayman Islands Turtle Farm, which began breeding green turtles in the 1970s.
Female green turtles, farm researchers discovered, mate multiple times, and have more than one father per clutch of eggs. But they made special note of female No. B100, who was "observed to mate 28 times in 12 days with six different males for periods between one and 13 hours," then laid a whopping 994 eggs for the season.
Researchers also noticed what later researchers dubbed "scramble polygamy" among male sea turtles. Instead of battling each other or defending a territory, they used speed and persistence to get girls. Even if it meant waiting for the male just below them to finish.
Moreover, the turtle farm found, turtle couples wouldn't mate without other males around to compete with. So with thousands of scrambling males and females like B100, things could get orgiastic in the turtle farm's breeding pools. It's no wonder the farm turned, in the 1980s, to semen extraction and artificial insemination.
The male turtles, apparently, liked it.
The process, as described in one report, sounded a bit harsh: A male would be lifted out of the water and tied to a metal rack with ropes before being stimulated, electrically, to ejaculate.
Sometimes it took the electric prod to cause a response. But "in some instances," the researchers wrote, "the penis would be extended as the male was secured to the rack."
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"Have you seen my turtle penises?" asked Pritchard, grabbing some jars off a cabinet.
Floating in one was a white, fleshy, arrow-shaped, somewhat flattened-looking member about 6 inches long with a groove down the middle.
It came from a hawksbill turtle in Guyana that, Pritchard explained, was dead more than a month before Pritchard got to it. By which time most of the turtle was skeletonized. But the penis, weirdly, was intact, "somehow immune to decomposition," tucked under the tailbones of the turtle.
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Given the kinky habits of greens and loggerheads (and Kemp's ridleys too -- the males bite like mad, according to turtle farm reports), it may be a relief to some that there's one species out there that's not only gentle, but practically monogamous.
National Geographic scientists have stuck small cameras, called "crittercams," to the backs of Costa Rican leatherbacks, allowing a rather up-close and personal view of their mating activity. They have no claws, so males hug, rather than clamp, the female.
Greg Marshall, an executive producer at National Geographic, said tremendous things have been learned from the leatherback pornography.
First, he said, no one realized how close to shore the males come in during the breeding season -- putting them in as much danger from fishing boats as females. Second, Marshall said, neither sex seems to eat at all during mating season.
But most surprisingly, he said, the females continue to "see" males even between nestings. They may avoid them, and head to shallow waters to run away from them, he said, but they're still interacting with them.
The scientists also found that nearly 99 percent of eggs in a leatherback nest are fertilized by the same male.
So if greens are sluts, leatherbacks are, well, teases. It's just how they happen to like it.