Color vision and signal color evolution in Anolis Lizards

Anolis is a diverse genus of small arboreal lizards that utilize a visual communication system using a colorful expandable throat-fan (dewlap). They signal either to attract females or repel males. The environment the lizard lives in has influenced the coloring of these dewlaps. Species that occupy shaded habitats tend to have yellow dewlaps while those that inhabit brighter habitats tend to have red dewlaps. In experiment 1 we used a color perception assay to test whether a red or yellow stimulus against a green background was more visible to the lizard under different light intensities mimicking a dewlap appearing in a forested or open habitat. Our results mirrored those predicted suggesting that yellow is more visible under low light while red is more visible under high light. In experiment 2 we used a similar assay with different stimuli to test the relationship between dewlap and background brightness independent of color to see if dewlap brightness directly influences detectability. The results weren\u27t significant suggesting that anoles do not signal in a particular place in their environment and do not take in account the background brightness when signaling. In experiment 3 we wanted to test how males interacted with each other and how varying body temperature could affect the signaling of a lizard. The lizards with a high or optimal body temperature (lights on) had a higher aggression score than those lizards that had a low body temperature (lights off). Anoles with a low body temperature were lethargic resulting in a decrease in amount and frequency of signaling