Ducks Can “Shut That Whole Thing Down” And Reject Sperm

“From what I understand from doctors, [pregnancy from rape] is really rare. If it’s a legitimate rape, the female body has ways to try to shut that whole thing down.”  –Missouri US Senate Candidate Todd Akin

That’s the (widely repudiated and much-repented-for) quote that swept across the nation and resulted in prompt calls for Senate candidate and US Rep Todd Akin to withdraw from the race for fear it will cost Republicans a chance at control of the upper chamber. (Akin said this afternoon he’s in it to win it, despite major GOP money sources saying they’re not going to fund him.)

To be clear, it’s totally nonsense (and Akin has admitted as much) that human women’s bodies can “shut that whole thing down” and reject sperm if raped. But interestingly, a 2008 episode of RadioLab explains that female DUCKS do have that capability. Fascinating. (Hat tip to my friend Reeve for pointing this out to me.) The audio of this discussion starts around the 13:15 mark, but I excerpted a key part here.

“The thing about the duck is … ducks engage in forced extra-pair copulations. What he’s really saying is the males are “raping” the females. A couple of years ago, we were dissecting a female duck and a doc called Patty Brennan (sp) called me and said “Look at this, I found a funny structure in the female vagina…

What we found was that in species where the male had an enormous phallus, the female had the most complex vagina we’d ever come across. Some have two or three side branches and a very long spiral, like a corkscrew at the end of the vagina. If you think about it, what seems very likely here is the female has got these structures to deflect the male. If she’s being raped, she might contract part of her reproductive tract to send the male off down a blind alley. If he avoids that, she can just tighten up the spiral so his sperm can’t get to the right place. So what you’ve got here is a kind of warfare. The male says, I’m coming in here like it or not, and the female says, you’re getting nowhere, like it or not. Remarkable case of females evolving counter-adaptations to keep males at arm’s length. Or penis length, so to speak.”