Lady ducks have evolved a unique way of avoiding the unwanted advances of, er, enthusiastic suitors, according to Yale scientists.
According to researchers, while male ducks have developed longer, spiraled genitalia, the females' anatomy has evolved to spiral in the opposite direction. “In species where forced copulation is common ... this coevolution results from conflict between the sexes over who is going to control fertilization,” said Yale researcher Patricia L.R. Brennan.
Essentially, female ducks are able to thwart "undesirable but aggressive males" and avoid becoming pregnant because the sexes have evolved mismatched equipment.
Researchers released the study this week detailing this evolutionary battle of the sexes in the current issue of journal Proceedings of the Royal Society B.
This latest paper builds off of a 2007 study that detailed the odd structure of ducks' sexual organs. For this study, scientists (presumably without blushing) examined the male ducks' genitalia in glass tubes meant to simulate the shape of a female's sex organ. Researchers observed that the ducks' incompatible parts prevented pregnancy in the females.
"Ducks are providing us with an incredible opportunity to understand the evolutionary consequences of conflict,” said Brennan.