Last month, Pat Robertson fretted that hate-crime legislation would lead to the protection of people who "like to have sex with ducks ." His remark resulted in a delightful Robertson-mocking pro-duck-sex song released last week by musical group Garfunkel and Oates . Robertson doesn't have to worry too much about human-on-duck sex - it's clearly illegal since quacking doesn't qualify as consent. But ducks are no innocent victims. Rather, their giant members and coercive sexual practices make them the perfect posterbird for heterosexual sex gone awry.
Most birds forgo genitalia for a single all-purpose opening called the cloaca. Waterfowl are the well-endowed exception. The Argentinian lake duck is the most impressive-one individual had a phallus as long as its entire body - but most ducks, geese, and swans have some kind of phallus. Female ducks have equally elaborate reproductive tracts , called oviducts, with spirals and twists and dead ends. (Incidentally, while male duck phalluses have been studied for years, no one noticed the ladies' oviducts until 2007, when researcher Dr. Patricia Brennan figured "Obviously you can’t have something like that without some place to put it in. You need a garage to park the car.")
Ducks with teeny weenies do live the nuclear family dream (at least for a season), with a daddy duck, a mommy duck, and some adorable little ducklings. But amongst the webfooted Ron Jeremys, phallus and oviduct size is related to sexual violence. Female ducks in large-phallused species choose a mate for the season, but other males will still try to forcibly copulate with her. Since several males can assault a single female, duck sex can be an alarming sight .
Though a duck female may not be able to avoid her attackers, researchers suggest that complicated internal anatomy prevents unwanted fertilization . In other words, if the female duck isn't into it, the bends and twists in her oviduct make it hard for the male to get his phallus position. Considering only 2 percent to 5 percent of ducklings are conceived during forced matings , most of that sperm probably ends up in one of the oviduct's dead ends.
If larger phalluses mean greater fertilization, male and female ducks could be locked into a competition, with males evolving larger and larger phalluses as females evolve twistier and turnier oviducts. Between the giant phalluses and the violence, anyone who wants to have sex with ducks is going to have to really commit to that lifestyle. Somehow, I don't think Pat Robertson has too much to worry about.
Image of male Argentine Lake Duck by K. McCracken/Nature.