Sexual selection and the differential effect of polyandry

Julie Collet, David S. Richardson, Kirsty Worley, Tommaso Pizzari

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

In principle, widespread polyandry (female promiscuity) creates potential for sexual selection in males both before and after copulation. However, the way polyandry affects pre- and postcopulatory episodes of sexual selection remains little understood. Resolving this fundamental question has been difficult because it requires extensive information on mating behavior as well as paternity for the whole male population. Here we show that in replicate seminatural groups of red junglefowl, Gallus gallus, polyandry eroded variance in male mating success, which simultaneously weakened the overall intensity of sexual selection but increased the relative strength of postcopulatory episodes. We further illustrate the differential effect of polyandry on pre- and postcopulatory sexual selection by considering the case of male social status, a key determinant of male reproductive success in this species. In low-polyandry groups, however, status was strongly sexually selected before copulation because dominants mated with more females. In high-polyandry groups, sexual selection for status was weakened and largely restricted after copulation because dominants defended paternity by mating repeatedly with the same female. These results reveal polyandry as a potent and dynamic modulator of sexual selection episodes.
Original languageEnglish
Pages (from-to)8641-8645
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America (PNAS)
Volume109
Issue number22
DOIs
Publication statusPublished - 2012

Keywords

  • cryptic female choice
  • sperm competition
  • selection gradient
  • opportunity of selection

Cite this