Duration of Tonic Immobility In Lizards (Anolis Carolinensis) as a Function of Repeated Immobilization, Frequent Handling, and Laboratory Maintenance

Abstract

Research has shown that chickens given repeated elicitations of the tonic immobility reaction, an habituation procedure, show larger decrements in duration of tonic immobility on a subsequent test trial than do either birds given simple handling or naive animals. The present study attempted to replicate this finding with another animal commonly used in studies of tonic immobility, the anole lizard (Anolis carolinensis). Experiment 1 employed the between-groups design used in previous studies and failed to detect differences among the three treatments (habituated, handled, and naive) in duration of immobility. A second experiment used a within-subjects measure of immobility duration to demonstrate that the habituation procedure and simple handling produce similar decrements in duration of immobility. The final experiment demonstrated that anoles maintained in a group-living situation, with some daily exposure to humans, also show reliable decrements in duration of immobility. These results are congruent with those obtained by Boice and Williams (1971) with frogs (Rana pipiens).