y you can’t have something like that without some place to put it in. You need a garage to park the car.”
The lower oviduct (the equivalent of the vagina in birds) is typically a simple tube. But when Dr. Brennan dissected some female ducks, she discovered they had a radically different anatomy. “There were all these weird structures, these pockets and spirals,” she said.
Somehow, generations of biologists had never noticed this anatomy before. Pondering it, Dr. Brennan came to doubt the conventional explanation for how duck phalluses evolved.
In some species of ducks, a female bonds for a season with a male. But she is also harassed by other males that force her to mate. “It’s nasty business. Females are often killed or injured,” Dr. Brennan said…
Dr. Brennan argues that elaborate female duck anatomy evolves as a countermeasure against aggressive males. “Once they choose a male, they’re making the best possible choice, and that’s the male they want siring their offspring,” she said. “They don’t want the guy flying in from who knows where. It makes sense that they would develop a defense.”
Female ducks seem to be equipped to block the sperm of unwanted males. Their lower oviduct is spiraled like the male phallus, for example, but it turns in the opposite direction. Dr. Brennan suspects that the female ducks can force sperm into one of the pockets and then expel it. “It only makes sense as a barrier,” she said.
I’m a little perplexed by this corkscrew business. Does the male need to, you know, spin around? I’m not the keenest birdwatcher, but I think I’d have noticed – in the park, maybe. “Mummy, what’s that duck doing, spinning round on top of that other duck?”
And those orientation problems: “Don’t you just hate it when you’ve lined up a cute dowdy little brown feather, pecked her into submission, then, uh-oh, wouldn’t you know, the bitch is anti-clockwise.”
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