Melanin-Based Coloration Covaries with Hiding and Exploratory Behavior in Male Spanish Terrapins

Melanin-based coloration reflects mostly social status and dominance in males of several species. However, the relation of melanism with other suites of behavioral traits has received less attention. Here, we examined whether the melanic coloration of the shell of male Spanish terrapins Mauremys leprosa was related to several behavioral patterns. To test this, we simulated predatory attacks of different risk levels and measured the time that the turtles spent hiding entirely in their own shells (i.e. appearance times). We also measured the activity level of the turtles in a novelenvironment test. The results showed that melanin-based coloration was related to antipredatory behavior. Male terrapins with a greater extent of black coloration in their shells demonstrated shorter appearance times after a predator attack. However, this pattern was significant only when turtles were subjected to a high risk. In addition, darker turtles had longer latency times in a novel environment. The results of the present study support the hypothesis that melanin-based coloration may be associated with some behavioral functions. Our study provides a good framework for future studies concerning the effect of melanin-coloration on multiple behavioral traits that could be applied to further research using other animal models