Dewlap size
We measured dewlap area and perimeter from digital photos in ImageJ. Dewlap area and perimeter were measured by creating line segments throughout the border of the dewlap, ultimately forming a polygon and obtaining the area and perimeter of it. We measured the dewlap for each lizard twice to verify the repeatability of this method, which was 1.0. We used a digital x-ray system to capture skeletal images from euthanized lizards. Using ObjectJ, a plug-in for ImageJ, we estimated of body size by measuring snout-vent length (SVL), the distance from the tip of the snout (i.e., the edge of the soft tissue) to the final vertebrae that had forward-facing arms. SVL values were then log-transformed and regressed against log-transformed dewlap area and perimeter. The resulting residual values represent body size-adjusted dewlap size.