Behavioral Ecology and Sociobiology

, Volume 66, Issue 1, pp 97–105

Genital morphology linked to social status in the bank vole (Myodes glareolus)

  • Jean-François Lemaître
  • Steven A. Ramm
  • Nicola Jennings
  • Paula Stockley
Original Paper

DOI: 10.1007/s00265-011-1257-4

Cite this article as:
Lemaître, JF., Ramm, S.A., Jennings, N. et al. Behav Ecol Sociobiol (2012) 66: 97. doi:10.1007/s00265-011-1257-4

Abstract

Since genital morphology can influence the outcome of post-copulatory sexual selection, differences in the genitalia of dominant and subordinate males could be a factor contributing to the fertilisation advantage of dominant males under sperm competition. Here we investigate for the first time if penile morphology differs according to male social status in a promiscuous mammal, the bank vole (Myodes glareolus). In this species, dominant males typically achieve higher reproductive success than subordinates in post-copulatory sexual selection, and male genital morphology is complex, including both a baculum (os penis) and penile spines. Our results show that despite no difference in body size associated with male social status, baculum width is significantly larger in dominant male bank voles than in subordinates. We also found evidence of positive allometry and a relatively high coefficient of phenotypic variation in the baculum width of male bank voles, consistent with an influence of sexual selection. By contrast, baculum length and three measures of penile spinosity did not differ according to male social status or show evidence of positive allometry. We conclude that dominant male bank voles may benefit from an enlarged baculum under sperm competition and/or cryptic female choice and that differences in penile morphology according to male social status might be important but as yet largely unexplored source of variation in male reproductive success.

Keywords

AllometryBaculumGenitaliaPenile spinesSexual selectionSocial dominanceSperm competition

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Jean-François Lemaître
    • 1
    • 3
  • Steven A. Ramm
    • 2
    • 3
  • Nicola Jennings
    • 3
  • Paula Stockley
    • 3
  1. 1.UMR CNRS 5558, Biométrie et Biologie EvolutiveUniversité Claude Bernard Lyon 1Villeurbanne CedexFrance
  2. 2.Evolutionary Biology, Zoological InstituteUniversity of BaselBaselSwitzerland
  3. 3.Mammalian Behaviour and Evolution Group, Institute of Integrative BiologyUniversity of LiverpoolNestonUK