Meeting Abstract

P3.218  Sunday, Jan. 6  Temperature-dependent behaviors in the Texas spiny lizard (Sceloporus olivaceus) BLACKMON, T.N.*; JOHNSON, M.A.; Trinity University, San Antonio; Trinity University, San Antonio tblackmo@trinity.edu

The maintenance of body temperature is a critical task for ectotherms, which rely largely on the temperature of their environment for thermoregulation. In reptiles in particular, many animals use behavioral mechanisms to control their thermal exposure; however, relatively little is known about variation in natural behaviors as a function of body temperature. In this study, we examined Sceloporus olivaceus (the Texas spiny lizard) in the field to determine the relationship between temperature and natural behavior in this species. We measured the internal body temperature and external perch temperature of 42 adult lizards, and found that internal body temperatures at the time of capture ranged from 26° to 41°C, with the average body temperature 34.5°C. We found no difference between the average temperature of males and females. As expected, our results also showed a strong positive correlation between the internal and external temperatures. In addition, we collected 33 hours of behavioral observations for 56 S. olivaceus, recording the frequency of two common behaviors (locomotion and push-up displays) performed by the lizards in full sun, partial sun, and full shade. These data suggest that males perform more locomotion behaviors and pushup displays while in the shade, while females have a higher rate of locomotion in full sun. Taken together, our findings suggest that though the sexes do not differ in average temperature, there may be sex-specific differences in the temperatures at which certain behaviors are exhibited.