When you find yourself, as I did a few days ago, spending a morning watching the absurdly long phalluses of ducks being coaxed from their nether regions, you can find yourself wondering how your life ended up this way. Fortunately, there is a higher goal to such weirdness. The phalluses of ducks are just the tip of an evolutionary iceberg. The female ducks have their own kinkiness, too. It's all part of a fierce avian battle of the sexes. For the latest, see my article in tomorrow's New York Times. The paper on which it is based appears in the open-access journal PLOS One. Update 5/1, 11 am: The gossips at Gawker discover the queasy fascination. Welcome to Nature.