| Many lizards maintain their body temperature within a fairly narrow range, despite spatial and temporal variation in microclimates. The ability to measure these temperatures is central to studying lizard physiology. Non-intrusive methods are preferred because they cause the least disruption to the animal's natural behavioral patterns. I modified the Alberts and Grant (1997) model of non-contact temperature prediction of Cuban rock iguanas (mass range 120-850 g) for use on four species of smaller lizards (mass range 2-7 g). I also developed an empirical model expressing the relationship between skin surface temperature (Ts) and internal body temperature (Tb) as a regression. Using this model, and given an ambient temperature (Ta), a lizard's internal body temperature can be estimated within 0.2 +/- 1.43 SD°C from its remotely determined dorsal skin surface temperature. The modified Alberts and Grant model and my model had similar predictive results. Additional potential heating and cooling rates were determined in the lab with various heat sources and sinks to assess the ability of lizard body temperatures to vary in the short term and to confirm the accuracy of our field readings. Chase studies in the lab showed that there was no significant change in the internal body temperatures of the lizards if they were chased to and from heat sources and sinks over a ten-minute period. The lizards appeared to be unable to maintain preferred laboratory temperatures precisely in the field. |
