UV coloration influences spatial dominance but not agonistic behaviors in male wall lizards

Abstract

A bright ultraviolet (UV) component in the colora- tionofmales may signalindividualqualityand thusdetermine the outcome of male-male contests. Yet, the role of the UV component of coloration in resolving conflicts is still contro- versial relative to factors such as residency status and season- ality. Here, we investigated whether a reduction of UVreflec- tance of lateral blue spots in male wall lizards (Podarcis muralis) interacts with residency status (resident vs. intruder) to influence agonistic behaviors, the outcome of contests, and basking time (a measure of spatial dominance). We performed this experiment during one breeding and one non-breeding season. The UV manipulation did not predict the outcome of contests. During the breeding season, the agonistic behaviors and basking time depended on the residency status of males but not on their UV treatment. During the non-breeding sea- son, experimental factors affected basking time only. For a given male, the time spent basking depended in a complex manner on its residency status, its UV treatment, and those of its rival. UV reflectance of blue spots thus influences the processes of mutual assessment and spatial dominance, but is not a criticaldeterminant offightingsuccess.Altogether, these results evidence context-dependent effects of the UV reflec- tance of blue spots on territorial behaviors according to resi- dency status and, potentially, season. They also suggest that UV signaling may be more important than expected for male- male interactions during the non-breeding season.