Question
What are the potential benefits of extra pair copulations for female animals?
Answer
Extra-pair copulations (EPCs) in female animals can offer several potential benefits, both genetic and material, enhancing their reproductive success and offspring viability.
Genetic Benefits
Increased Genetic Diversity: Females engaging in EPCs can increase the heterozygosity of their offspring, leading to higher survival rates and reproductive success due to reduced inbreeding [1] [2].
Good and Compatible Genes: By mating with multiple males, females can select for ‘good genes’ or ‘compatible genes’, improving the genetic quality of their offspring. This can result in offspring with better survival traits and secondary sexual characteristics [1] [3] [4].
Material Benefits
Access to Resources: Females that engage in EPCs may gain access to additional resources, such as feeding opportunities on the territories of extra-pair males, which are otherwise denied to females that remain faithful to their social mates [5].
Increased Protection: Extra-pair males may assist in defending the nest against predators, thereby increasing the survival chances of the offspring. This cooperative behaviour is often motivated by the extra-pair males’ interest in protecting their genetic investment [6] [7].
Reproductive Success
Improved Hatching and Fledging Success: Females that engage in EPCs often experience higher hatching and fledging success rates. This is attributed to reduced depredation and starvation rates in broods with mixed paternity [8] [5].
Flexible Mating Strategy: Females may adjust their mating behaviour based on previous breeding experiences, potentially increasing their reproductive success in subsequent attempts [2].
Summary
Engaging in extra-pair copulations can provide female animals with significant genetic and material advantages, enhancing both the quality and survival of their offspring. These benefits include increased genetic diversity, access to additional resources, and improved protection and reproductive success.
References
- Foerster, K., Delhey, K., Johnsen, A., Lifjeld, J., & Kempenaers, B. Females increase offspring heterozygosity and fitness through extra-pair matings. Nature. 2003; 425. https://doi.org/10.1038/nature01969
- Mennerat, A., Charmantier, A., Jørgensen, C., & Eliassen, S. Correlates of complete brood failure in blue tits: could extra‐pair mating provide unexplored benefits to females?. Journal of Avian Biology. 2018; 49. https://doi.org/10.1111/JAV.01701
- Pryke, S., Rollins, L., & Griffith, S. Females Use Multiple Mating and Genetically Loaded Sperm Competition to Target Compatible Genes. Science. 2010; 329. https://doi.org/10.1126/science.1192407
- Kempenaers, B., Verheyen, G., Broeck, M., Burke, T., Broeckhoven, C., & Dhondt, A. Extra-pair paternity results from female preference for high-quality males in the blue tit. Nature. 1992; 357. https://doi.org/10.1038/357494A0
- Gray, E. Female red-winged blackbirds accrue material benefits from copulating with extra-pair males. Animal Behaviour. 1997; 53. https://doi.org/10.1006/anbe.1996.0336
- Eliassen, S., & Jørgensen, C. Extra-Pair Mating and Evolution of Cooperative Neighbourhoods. PLoS ONE. 2014; 9. https://doi.org/10.1371/journal.pone.0099878
- Krams, I., Mennerat, A., Krama, T., Krams, R., Jõers, P., Elferts, D., Luoto, S., Rantala, M., & Eliassen, S. Extra-pair paternity explains cooperation in a bird species. Proceedings of the National Academy of Sciences of the United States of America. 2022; 119. https://doi.org/10.1073/pnas.2112004119
- Gray, E. Do female red-winged blackbirds benefit genetically from seeking extra-pair copulations?. Animal Behaviour. 1997; 53. https://doi.org/10.1006/anbe.1996.0337
