Behavioral threat and appeasement signals take precedence over static colors in lizard contests.

This article investigates the roles of morphological and behavioral signals in male-male contests of the common wall lizard (Podarcis muralis), focusing on how these signals influence contest outcomes and intensity. The study finds that males with greater black melanin-based coloration tend to win contests and exhibit higher aggression, but black coloration does not appear to be used by rivals for assessment during fights. Instead, behavioral displays—specifically raised-body postures (offensive threat signals) and Type II foot shakes (de-escalation signals)—are stronger predictors of contest outcome and winner aggression, suggesting these behaviors convey motivation rather than fixed intrinsic quality. Contest intensity is primarily influenced by self-assessment and resource value rather than mutual assessment of morphological traits, with males likely using behavioral signals to communicate willingness to escalate or withdraw. These findings highlight the importance of dynamic behavioral signals over static morphological traits in contest assessment within territorial lizard social systems.