Meeting Abstract

27.7  Friday, Jan. 4  The role of badge size, bite performance and display behavior in predicting dominance in male ornate tree lizards. MEYERS, J.J.*; IRSCHICK, D.J.; University of Massachusetts, Amherst; University of Massachusetts, Amherst jmeyers@bio.umass.edu

Social dominance among males has a profound effect on fitness in many species. Yet the characteristics that make up winners of agonistic interactions are not always clear and are often complex. Dominance interactions are often mediated by status signaling badges and variation in badge size has been shown to signal differences in performance capacity (e.g. bite force). While large badges and high performance capacity often indicate dominant individuals, one thing that remains unclear is whether these high quality males are the same individuals that display frequently and act dominant in their natural environment. In this study we incorporate several important components of dominance interactions (badge size, performance capacity and natural display behavior) to determine which traits are most important in determining social dominance. We examined these relationships in the ornate tree lizard (Urosaurus ornatus), which is a polygynous species with colorful throat and belly patches that are readily displayed during agonistic interactions. We captured male U. ornatus in a mesquite bosque in southern Arizona and measured badge size, morphology and bite force performance. These animals were then released and over the following month the natural display behavior of 47 individuals was filmed. Lastly, a subset of the original animals was recaptured and size-matched for paired competition trials used to determine dominance. Our findings suggest that no single trait predicts the winners of agonistic interactions and reveals the importance of an integrated approach to studying dominance contests.