More melanized males bite stronger but run slower

Ondertitel:potential performance trade-offs related to melanin-based coloration

Although the signalling role of melanin-based coloration has been largely debated, an increasing number of studies support its relationship to different fitness-related traits. However, whether melanin-based coloration could also function as an indicator of performance has been barely explored despite the influence that performance has on fitness. We investigated the relationship between melanin-based coloration and bite force and sprint speed in male common lizards, Zootocavivipara. Melanin-based coloration predicted performance, being positively and negatively related to bite force and sprint speed. The association between melanin-based coloration and bite force is mediated by positive associations between coloration and head and body size. We did not find an association between coloration and any morphological traits determining sprint speed and the driver of the encountered negative association remains unknown. The observed opposite relationships between coloration and performance traits suggests the existence of costs (e.g. darker males may have higher predation because of lower sprint speeds) and/or alternative performance strategies, which is congruent with disruptive selection on sprint speed in juvenile common lizards. Our findings suggest that melanin-based coloration could indicate performance capacity, a hypothesis that deserves further attention considering that, as shown here, more intense coloration may not necessarily reflect a better overall performance.

Jaar van publicatie:2017