Behavioral Ecology and Sociobiology

, Volume 67, Issue 1, pp 79–90

The role of size and aggression in intrasexual male competition in a social lizard species, Egernia whitii

  • Jo McEvoy
  • Geoffrey M. While
  • David L. Sinn
  • Erik Wapstra
Original Paper

DOI: 10.1007/s00265-012-1427-z

Cite this article as:
McEvoy, J., While, G.M., Sinn, D.L. et al. Behav Ecol Sociobiol (2013) 67: 79. doi:10.1007/s00265-012-1427-z

Abstract

Competition between males is a key component of the agonistic intrasexual interactions that influence resource acquisition, social system dynamics, and ultimately reproductive success. Sexual selection theory predicts that traits that enhance success in intrasexual competition (particularly male–male competition) should be favored. In vertebrates, this often includes body size and aggression, with larger and/or more aggressive males outcompeting smaller or less aggressive conspecifics. The majority of studies consider aggression as a flexible trait which responds to local social or environmental conditions. However, aggression frequently shows considerable within-individual consistency (i.e., individuals have identifiable aggressive behavioral types). Little is known about how such consistency in aggression may influence competition outcomes. We integrated a detailed field study with a laboratory experiment to examine how a male’s aggressive phenotype and his size influence competitive interactions in Egernia whitii, a social lizard species which exhibits strong competition over resources (limited permanent shelter sites and basking sites). Individual aggression and size did not predict competition outcome in the laboratory nor did they predict home range size, overlap, or reproductive success in the field. However, winners of laboratory trial contests maintained consistent aggressive phenotypes while consistency in aggression was lost in losers. We suggest that aggression may be important in other functional contexts, such as parental care, and that alternative traits, such as fighting experience, may be important in determining competition outcome in this species.

Keywords

Intrasexual male competitionPersonalityAggressionLizardBehavioral consistencyBehavioral plasticity

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Jo McEvoy
    • 1
  • Geoffrey M. While
    • 1
    • 2
  • David L. Sinn
    • 1
    • 3
  • Erik Wapstra
    • 1
  1. 1.School of Zoology, University of TasmaniaHobartAustralia
  2. 2.Edward Grey Institute, Department of Zoology, University of OxfordOxfordUK
  3. 3.The University of Texas at Austin, Department of PsychologyAustinUSA