Article Review - Color Change in Panther Chameleons

    Panther chameleons have two layers of specialized cells, known as iridophores, within their skin that contain nanocrystals. By relaxing or exciting their skin they are capable of manipulating these nanocrystals and reflect different wavelengths to change color. There are several functions to this unique trait, such as maintaining a stable body temperature, attracting mates, reflecting their mood, and defending their territory. Chameleons are not the only squamate that utilize color as means of combative behavior and establishing dominance, for example, within the family Dactyloidae, anole lizards can gauge how strong their opponents are based on how colorful their dewlap is. Research on this topic is important in understanding the evolution of diverse methods of communication within squamates. 

    Researchers examined changes in behavior and color (visible and UV) to better understand how the male panther chameleon, Furcifer pardalis, utilizes their color change ability to express their dominance in male-male combative displays. After many trials of combative encounters, researchers found that the males with more prominent coloration on their bands were more likely to win the encounter and take control over the territory. Losers of the altercation exhibited much darker colors which can be identified as a sign of submission. They also found evidence of UV coloration but it did contribute to the victory of the more dominant male so it is likely for another purpose, such as attracting mates or most likely a defense mechanism to avoid being eaten by birds because birds struggle to see the UV wavelength emitted by F. pardalis. 

    In conclusion color change in chameleons can function in a variety of different ways. There is still lots of possibilities for future research, for example, studies that examine the cost to benefit ratio for energy expenditure would provide insight on the impact color change has on thermoregulatory mechanisms of chameleons. 

Citation:

Dollion, A. Y., Meylan, S., Marquis, O., Leroux-Coyau, M., & Herrel, A. (2022). Do male panther chameleons use different aspects of color change to settle disputes? Die Naturwissenschaften., 109(1). https://doi.org/10.1007/s00114-022-01784-y