Color changing behavior has been widely documented in many lizard taxa.For example, the green anole (Anolis carolinensis) can rapidly transition from a uniform green to brown-colored. In those taxa where color change is rapid (including the green anole), such behavior has been attributed to communication of socially relevant information such as aggression or dominance. However, what information is conveyed through color change in A. carolinensis during social interactions remains an open question. Brittney Ivanov, a research technician in Michele Johnson’s lab at Trinity University performed experiments in captivity using lizards captured from the wild to examine this question.
Brittney captured 12 lizards of each sex, which were checked daily for coloration to assess the predominant coloration of each individual. She then paired lizards from the opposite sex and placed them together for 2 weeks to determine if coloration is used differently between naïve and novel pairs. Lastly, same-sex trials were performed in both male and female lizards to determine if coloration indicates higher social status.
Brittney found that males spent more time being green compared to females and that their predominant body color was consistent across social context or housing condition (living alone versus with a female). Predominantly green males also “won” more often in same-sex trials. Female coloration was not associated with the results of the same-sex trials, but females were found to be green more often when housed alone than when housed with a male. Brittney’s research suggests that coloration may be used differently between male and female green anoles and that for males, coloration may determine social status or competitive ability.