With all the interest in duck sex these days, a lecture by the scientist who discovered gay mallard necrophilia seems timely.  

In a TED Talk posted online this month, Dutch biologist Kees Moeliker, a curator at the Natural History Museum Rotterdam, explains how he became the first scientist to document homosexual necrophilia in ducks.

Moeliker was working in a new glass wing at the museum that turned out to be a "true bird killer." Not understanding the concept of glass, birds were constantly flying into windows and dying upon impact. On June 5, 1995, Moeliker heard the bang that changed his life.

On that day, when he looked outside for the building's latest victim, Moeliker saw the hapless male mallard with a live one nearby. The live male duck then mounted the dead one and started copulating with it.

"I'm a biologist. I'm an ornithologist. I said, 'Something's wrong here. One is dead; one is alive; that must be necrophilia. And, look, both are of the male sex — homosexual necrophilia,'" Moeliker told the audience. Ready to take notes, the researcher went outside and watched the live duck trying to have sex with the corpse for 75 minutes before picking up the dead bird and freezing it.

"I knew I had seen something special, but it took me six years to decide to publish it," Moeliker said in his talk. The research earned him the 2003 Ig Nobel biology prize, and now that Moeliker has made a name for himself in the realm of animal-sex oddities, people all over the world send him their own peculiar observations.

"Believe me, if there's an animal misbehaving on this planet, I know about it," Moeliker said, showing examples of the pictures he has received: a moose trying to copulate with a bronze statue of a bison in Montana; a frog trying to have sex with a goldfish in the Netherlands; and a cane toad trying to have sex with a victim of road kill (notably in the missionary position — a rarity in the animal kingdom).

Moeliker has used the anniversary of his strange discovery (June 5) to hold a "Dead Duck Day" at the museum, where researchers discuss with the public new ways to prevent birds from colliding with windows.

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