A duck pond in the breeding season is like a singles bar on steroids -- rife with sexual conflict. Males and females pair off, but male ducks also force sex on females that are not their mates, sometimes injuring or even killing them.
A few years ago, one of us (Patty Brennan) discovered that these extreme sexual behaviors have sparked an evolutionary arms race between male and female ducks – a race that has changed the shape of their reproductive organs. Females evolved twisty, complicated oviducts that make it difficult for males to put sperm near their eggs.
Males countered by evolving long and twisty penises that rapidly inflate inside the oviduct. The bends and blind alleys in the oviduct seem to be effective at keeping out sperm from unwanted males. But during one of her experiments, Patty noticed that an inflating drake’s penis could burst through a silicone model of an oviduct.
That made her wonder whether the forces produced by explosive eversion could be one factor driving the evolution of the female’s twisty oviduct. To find out, Patty is teaming up with biomechanics expert Diane Kelly to measure the speed and force of the inflating duck penis and determine how it might affect the female’s reproductive tract.
What exactly do we plan to do?
Your contributions will let us travel to a farm in Quebec, Canada that has trained male ducks to provide sperm for artificial insemination. We will let these ducks copulate with a series of transparent model oviducts fitted with force transducers – the process is harmless to the ducks, and isn’t much different from the way the farmers collect sperm. As each duck everts his penis, we will simultaneously film it with high-speed video and measure how hard it hits the wall of the model oviduct.
What will the funds be used for?
Donations will help pay for the construction of model oviducts containing force transducers, as well as our travel and lodging in Quebec. And if we raise more than 100% of our goal, we'll use the money to expand the study and measure the strength and toughness of oviduct tissue. Through the entire project, we’ll let you (virtually) tag along through the stories and video we add to our project blog.
What will this experiment produce?
If successful, this project will provide the first detailed measurements of the physical forces generated by a penis during copulation. It will take the first steps toward testing whether copulatory forces help drive the evolution of those crazy twists in the female’s oviduct. We expect to present these results in talks at scientific conferences and write them up in a paper for a peer-reviewed scientific journal.
Helping to fund this research will let you contribute to our understanding of both the biomechanics of reproductive systems and the role of sexual conflict in the evolution of reproductive structures.
And really, don’t you just want to know?
******Part of the #SciFund Challenge