CARLISLE, E; IRSCHICK, D; Tulane University: Morphology, Behavior, and Habitat Use in Two Populations of Anolis carolinensis

Animals in environments that differ in the diversity and abundance of predators often modify their response to potential threats. We quantified the escape response of male and female green anoles (Anolis carolinensis in two habitats that differ markedly in habitat structure and the intensity of predation. One population (Good Hope Field) is a seasonal freshwater swamp that contains many potential anole predators, such as snakes, birds, and invertebrates. The other population (Tulane University campus) consists of largely cultivated strands of large palmetto leaves, and in which predation intensity is very low. We predicted that lizards in the Good Hope Field population should flee sooner (longer escape distances) in response to a threat, as the risk of predation is much higher in that habitat. We detected both habitat and sex effects. As predicted, lizards in the high-predation habitat fled sooner compared to the low-predation habitat, but we also found that in both habitats, females fled sooner than males. However, we detected no significant differences in the total distance fled either between habitats, or between sexes within either habitat. The mode of escape used also differed between habitats, as lizards in the leafy low-predation habitat tended to flee downwards into the dense base of the leaf clumps, whereas in the more cluttered high-predation environment, lizards tended to flee more typically upwards. Our findings indicate that green anoles have modified their behavior dramatically in response to occupation of two very different environments.