The dolphin has one that is spiral-shaped and filled with shutters. The ring-tailed lemurs disappear and the opossum has three.
Welcome to the wild, weird and woefully ignored world of animal vaginas.
There are vaginas that look nothing like vaginas, such as the spider monkey’s pseudo-penis or the hyena’s 20 cm clitoral tube from which she urinates, parries, and gives birth.
“Biologists love penises,” writes Rachel Gross in “Vagina Obscura” (Norton), noting that the vagina has typically been given short shrift by animal researchers. “They are also easy to study. Penises hang out a bit.”
The field has suffered from the long-held belief that vaginas were merely passive receptacles—a prejudice that extended to females in general. Gross calls this “vagina neglect.” Mount Holyoke biology professor Patricia Brennan, who has studied vaginas for nearly two decades, calls it “the copulative black box.”
The 2014 “Genital Evolution: Why Are Females Still Understudied” study found that 49% of papers published in the past 25 years studied only male genitalia, compared to 8% that focused solely on the female anatomy. “We argue that understanding genital evolution is hampered by an outdated single-gender bias,” the paper reads.
In the past decade, however, there has been an overhaul of the study of animal genitalia, as long-established beliefs cannot withstand scrutiny.
Vaginas are finally having their day in the sun — especially in Lucy Cooke’s rambunctious new book “Bitch: On the Female of the Species” (Basic Books), out now.
“In the natural world, the female form and role varies wildly to encompass a fascinating spectrum of anatomy and behavior,” writes Cooke, an author, TV personality, zoologist and self-proclaimed explorer. This new understanding of female anatomy “redefines not just the female of the species, but the forces that shape evolution.”
Grandfather of evolutionary biology Charles Darwin wrote that “genitals do not concern us” and largely avoided the subject. Females were then seen as less evolved versions of males – smaller, more immature, less aggressive. Females maintained the Victorian standards of the time, or “the reserved woman,” as Darwin described. Animal behavior textbooks wrote about the “reticent woman and the fiery man.”
Amid mounting evidence to the contrary, Colombian biologist Patricia Brennan began studying vaginas.
She started with the mallard. After finding a spiral, worm-like penis in blue-gray birds called tinamou in Costa Rica (when 97% of birds have no external genitalia), she turned her attention to the duck. When she discovered the fowl’s huge, corkscrew-shaped phallus and the disturbing sexual act that accompanied it, she nearly fell off her chair. She wondered: what did the accompanying vagina look like?
She discovered they were just as intricate, filled with Byzantine crevices and dead-end alleys. During regular copulation, the female anatomy works counterclockwise to that of the male. When copulation is forced—which is often the case—a female duck’s elaborate anatomy protects them with tooth-like cavities.
Brennan’s duck work “transformed scientific thinking and rehabilitated the woman from passive victim to active representative of her own evolutionary destiny,” Cooke writes.
But duck sex was just the “gateway drug.” Other animals followed, including the dolphin, which has strikingly similar spiral sex organs. “Convergent evolution with a duck!” Brennan said to Cooke. “It’s crazy!”
Like ducks, female dolphins can move their bodies and force a penis into a dead end. “Females have developed creative ways to control the insemination of their eggs, even when the males are more powerful, numerous or more powerful,” Cooke writes.
The battle of the sex organs often has major evolutionary implications. For example, when male mosquitofish develop longer genitals, the brains of the females expand “in order to outsmart their aggressors.”
Finally, Brennan set himself a new goal of compiling the world’s first physical library of animal vaginas.
“So many vaginas, such a short life,” Brennan told Cooke.
Her research revealed just how adaptable the organ is: For example, the female genitalia of the dogfish change shape and become more asymmetrical during pregnancy to accommodate pups. But nothing is more remarkable than the opossum, who has a surprise vagina that disappears “like a secret door” after delivery. Opossum also has two wombs, two ovaries and two other vaginas.
There are female moles with “balls,” called ovotestes, which are made up of both ovarian and testicular tissue. The ovaries produce eggs and the testes make testosterone, but not sperm, to amplify the mole’s aggression and body mass. These parts of the body shrink and expand depending on the need and the breeding season.
Then there are all the false phalluses. Madagascar’s fossa, which Cooke describes as a “cougar with a shrunken head,” actually grows an “internal bone” that looks like a male penis, even secreting a yellow fluid on the underside. The pretend penis disappears when the fossa is old enough to mate. Researchers believe it evolved to “protect them from unwanted attention from older males and territorial females.”
The ring-tailed lemur also has a pseudo-scrotum and an elongated clitoris that is almost identical to a lemur penis. They could, if they wanted, “write their names in the snow,” joked one lemur researcher.
Genitals evolve faster than any other body part, Cooke writes, and Brennan and other researchers believe that women actually play a greater role in genital natural selection than men, thereby acting as more active agents of evolution than any previous male-focused researchers could have imagined. .
Another interesting find from Brennan is the dolphin’s “enormous clitoris” which is “dense with erectile tissue and blood vessels and shaped remarkably like a human clitoris.”
Although researchers have long witnessed sexual behavior in dolphins outside of copulation — clitoris rubbing against the noses of other dolphins, for example, or against objects on the seafloor, no one had gone one step further to study clitoral function.
Brennan and colleagues dissected clitoral samples from dolphins and found webs of nerve endings and spongy tissue that allowed for swelling in areas easily accessible to the outside. Interestingly, dolphins are far from the only animal with clitoris – all mammals have one.
Everyone knows the penis-fencing male bonobo monkeys, but what about the bonobo female’s huge “cantaloupe-sized” clitoris? Some bonobo researchers believe that the clitoris—in a forward-facing position like a human’s—”[s] mutual stimulation with other women.” Bonobos engage in genital to genitalia with other females, and will often prefer this act to sex with males.
These animals engage in sexual acts outside of the necessity of making babies. Sex therefore serves “richer and more complex purposes than just the transfer of semen from one party to another . . . It can be used to strengthen friendship and alliances, make gestures of dominance and submission, as part of social negotiations,” writes Rachel Gross, author of “Vagina Obscura.”
For decades, female sex outside of copulation was dismissed as aberrant along with female aggression. Many researchers “look the other way when they encounter flirtatious females.” The reality is that only 7% of species are sexually monogamous.
A female lion will mate with multiple male suitors up to 100 times a day during heat. Chimpanzees border on “nymphomania, especially when they’re ovulating” — and animals like orangutans and marmosets have sex during their cycle if there’s no chance of getting pregnant.
The lopi antelope is a prime example of how bias has clouded research. When Darwin noticed the female’s powerful horns, he dismissed it as “a waste of life force.”
Boy, was he wrong. Women are not only horny, they are sexual aggressors. During their short fertility window, “it’s not uncommon to see males succumb to exhaustion as the demands of the female become too much for them,” Cooke writes.
Females battle it out for the finite sperm reserves and will even charge a “top stallion” to stop copulation with another female. As a result, the male takes on the “traditionally picky role of the female to conserve precious sperm.”
“Women are not destined to be passive and reserved, evolutionary side effects waiting to be dominated by men,” Cooke writes. Learning about the vast differences in female form and function “leaves me empowered by the boundless possibilities of the female experience.”