Prey detection in juveniles of an agamid lizard, Calotes versicolor (Daudin, 1802) (Reptilia: Squamata)

The relative importance of visual and chemical cues of prey in their detection by the juveniles of Calotes versicolor was studied using laboratory-born, 2-month-old individuals starved for 48hrs. Grasshoppers served as the prey in all experiments. In trials with deionized water and cologne water (pungency control), the lizards showed no tongue flicking. Presentation of prey-body chemical cues on cotton swabs also did not evoke tongue flicking in test lizards indicating a lack of response to different odors through the vomeronasal olfactory system. The same test lizards lunged at the transparent glass beaker housing an active prey, with their mouth open as if to catch it. They showed no tongue flicking. In contrast, when an immobile prey was presented similarly the test lizards ignored it. Apparently, chemical cues are of little value in prey detection in C. versicolor. The study shows that C. versicolor juveniles use visual cues and prey movements in detection and capture of prey.