Waters, RM; Bowers, BB; Burghardt, GM; ,
Despite the taxonomic, behavioral, and lifestyle diversity among reptile species, behavioral consistency in reptiles has not been examined to the extent that it has been in fish, birds, and mammals. Careful use of terms such as individuality, temperament, personality, and behavioral syndromes is needed as they carry overlapping connotations and varying dangers of being applied in an anthropomorphic fashion. The majority of research on such phenomena in reptiles has utilized snakes and lizards. Studies on antipredator behavior in natricine snakes, primarily in the genus Thamnophis, has produced strong evidence of individual consistency of behavior over time, some evidence for consistency across situations, clear evidence for a heritable basis for individual differences in antipredator behavior, and limited evidence linking individual variation with fitness-related outcomes. Research in lizards has mirrored findings reported for other vertebrates, focusing on one or more of five traits: shyness–boldness, exploration-avoidance, activity, sociability, conspecific aggression, and possible relationships among them. We review the methodology and statistical analyses used to study these traits in lizards and the relationships of these traits to morphology, reproduction, hormones, fitness, life history, and other factors. The common lizard (Zootoca vivipara) has become a model species, for example, in studies assessing the pace-of-life hypothesis, with results differing from those found in other vertebrates. Studies on turtles and crocodilians are also presented that further illustrate the comparative and methodological value of reptilian studies.