Meeting Abstract

47.4  Monday, Jan. 5  Testosterone and performance in a population of color polymorphic lizards HUYGHE, K.*; HUSAK, J.F.; VANHOOYDONCK, B.; HERREL, A.; MOORE, I.T.; VAN DAMME, R.; University of Antwerp, Belgium; Virginia Tech University; University of Antwerp, Belgium; Harvard University; Virginia Tech University; University of Antwerp, Belgium katleen.huyghe@ua.ac.be

Through their direct action on behavior or through their influence on morphology and performance, circulating testosterone levels can be mediators of aggressive displays and interactions. We tested these ideas in a population of lizards, which exhibits a distinct and striking color polymorphism. Males occur in 3 different colors (white, yellow, orange), providing an opportunity to test the idea that morphs are alternative solutions to the evolutionary challenges posed on the link between hormones, morphology, performance, and behavior. Our results show that morphs differ in size, and bite force capacity, but do not differ in locomotor performance. Here, we provide data to test the hypothesis that these differences are related to differences in steroid hormone levels between morphs, suggesting a balance between different fitness effects. Secondly, we test for the presence of a correlation between testosterone and different performance traits, as organismal performance can be expected to be important in mediating the outcome of aggressive male-male interactions and may play a role in female choice.