Habitat Light and Signal Color Evolution in 5 Species of Anoles from the Dominican Republic and the use of a Feeding Assay to test the Effects of Visual Color Contrast on Stimulus Visibility in the Lizard Anolis sagrei
Date of Award
Bachelor of Science
dewlap, background, worms, radiance, irradiance
Anolis lizards have excellent color vision and depend on their eyesight to detect visual signals made by other anoles. The dewlap, a colorful and expandable flap of skin, lies beneath the jaw in male anoles and is a primary signaling structure used for territorial and courtship displays. This paper focuses on dewlap color diversity and its evolutionary rudiments. With this in mind, the research team traveled to the Dominican Republic and collected natural habitat light data and dewlap and body color data from the local anoline inhabitants. We hypothesized that light environment would be the main driver behind dewlap color diversity. However we found that among the five species we sampled, which all had different dewlap colors, that the light environments were indistinguishable. We think that instead driving dewlap color diveristy, habitat light environment may set the constraints to which dewlap colors can be utilized in specific environments. In a laboratory at Union College, we ran three experiments using a feeding assay to test how anoles visually discriminate objects. In one experiment we manipulated hue, in another we manipulated hue and luminance, and in the third we manipulated hue in a lowlight setting. We hypothesized that hue contrast would allow for easier detection, however, we believed that when luminance contrast was also present hue contrast would be less important for object detection. The data supported both hypotheses. Unfortunately the anoles failed to respond in the final experiment, preventing us from making any presumptive conclusions.
Farmer, Raymond, "Habitat Light and Signal Color Evolution in 5 Species of Anoles from the Dominican Republic and the use of a Feeding Assay to test the Effects of Visual Color Contrast on Stimulus Visibility in the Lizard Anolis sagrei" (2016). Honors Theses and Student Projects. 146.