The Use of Color Vision & Color Communication in Lizards

The reptile genus Anolis is a widespread and diverse group in the Caribbean region of North and South America. Most anoles have a colorful throat flap known as the dewlap, which they likely use for social behavior and communication. Dewlaps vary between anole species in terms of color and thickness (related to brightness). It has been experimentally demonstrated that anoles can detect a stimulus based on chromatic contrast and brightness contrast of the stimulus to the background. Therefore, we hypothesized that anole color diversity in the Puerto Rican anoles evolved to either (1) contrast the habitat background to appear detectable or (2) appear different than other dewlap colors which function for species recognition. We sampled light spectra at display sites for four anole species and gathered dewlap reflectance and transmission data for six dewlap species (seven dewlap colors). We also generated 82 random dewlap colors. We compared the detectability and chromatic contrast to the background for actual dewlaps and random dewlaps, in each environment. The actual Puerto Rican colors were all consistently more similar with each other, than random colors were with the Puerto Rican dewlaps. This observation does not support our species recognition hypothesis. Three of the five dewlaps were more detectable in their home habitat than 50% of the random dewlaps. It is unclear whether dewlaps are evolving towards being more detectable than random based on this small sample