Males have notable color patches on the sides of the belly and throat. They are used during mating rituals and as a sign of dominance when fighting with other males (Lankilde and Boronow, 2012). Color of the patches varies with body temperature. At low temperatures, the badges are green, whereas they turn blue at higher temperatures. It has been proposed that this color change is used as a signal for both predators and competing males as a time of weakness. The belief is that when the lizards are green they are less mobile due to the decresed body temperature. (Lankilde and Boronow, 2012) Juveniles, however, lack the colored patches (Tinkle and Ballinger, 1972).
Langkilde, T., and Boronow, K. E. 2012. Hot boys are blue: Temperature-dependent color change in male eastern fence lizards. Journal of Herpetology 46: 461-465.
Tinkle, D. W., and Ballinger, R. E. 1972. Sceloporus undulatus: A study of the intraspecific comparative demography of a lizard. Ecology 53: 570-584.