Since there is a lot of male competition to further the lineage in ducks, males have to go to all sort of “lengths” to make sure their sperm makes the final cut and there is a “ducky daddy”.
But, females never go willingly into the mating ritual. Females do everything possible to thwart reproduction – including contorting their vaginas.
Male ducks, not to be outdone by the crafty female ducks’ aversions, will then deploy odd shaped penises to outdo the female. See pics here.
Research has shown that having a larger population of male ducks around will make a male duck’s penis 15% longer than if he was one of a few males around.
If the female duck doesn’t want to have any hanky-panky despite being in heat, the male duck will rape her.
There is definitely no love among ducks.