Question
Does a duck’s corkscrew penis give them some sort of breeding advantage?
Answer
The corkscrew-shaped penis of ducks, particularly in species like the Argentine lake duck, is believed to provide a breeding advantage through sexual selection mechanisms. This unique morphology may confer advantages in male-male competition and female choice.
Breeding Advantages
Runaway Selection and Female Preference: The corkscrew shape and length of the duck’s penis may have evolved due to runaway selection, where males with longer penises gain dominance and have more mating opportunities. Females might also prefer males with longer and more elaborately decorated penises, potentially leading to increased reproductive success for these males [1] [2].
Male-Male Competition: In species with high levels of male competition, such as ducks, penis length and elaboration are positively correlated with forced extra-pair copulations. This suggests that longer penises may provide an advantage in securing copulations in competitive environments [3] [4].
Sexual Conflict and Antagonistic Coevolution: The evolution of the duck’s penis is also influenced by sexual conflict, where males and females have opposing reproductive interests. The elaborate penis morphology may have developed as a result of this conflict, allowing males to overcome female resistance during mating [4].
The corkscrew penis of ducks likely provides a breeding advantage through mechanisms of sexual selection, including female preference and male-male competition. This morphology may help males secure more mating opportunities and overcome female resistance, thus enhancing reproductive success.
References
Brennan, P., & Adkins-Regan, E. Endocrine regulation and sexual differentiation of avian copulatory sexually selected characters. Neuroscience & Biobehavioural Reviews. 2014; 46. https://doi.org/10.1016/j.neubiorev.2014.08.010
McCracken, K., Wilson, R., McCracken, P., & Johnson, K. Sexual selection: Are ducks impressed by drakes’ display?. Nature. 2001; 413. https://doi.org/10.1038/35093160
Mead, C. Conservation biology: Ducks and darkes. Nature. 2000; 407. https://doi.org/10.1038/35035183
Brennan, P., Clark, C., & Prum, R. (2009). Explosive eversion and functional morphology of the duck penis supports sexual conflict in waterfowl genitalia. Proceedings of the Royal Society B: Biological Sciences. doi:10.1098/rspb.2009.2139
