Meeting Abstract
The insular giant chuckwalla (Sauromalus varius) provides a novel opportunity to study thermoregulatory behaviors not yet researched in this larger-sized reptile. This descriptive study aims to determine the preferred temperature range of S. varius in an enclosed thermal gradient, and compare that temperature range with their selected temperature in a semi-natural outdoor enclosure. iButton thermal dataloggers were attached to six giant chuckwallas using a gaffer tape vest technique. The lizards were then individually placed within the thermal gradient and observed for twelve hours. Temperatures in the outdoor enclosure were measured using iButtons placed inside seven copper models. iButtons were also attached to the giant chuckwallas and the copper models were placed at the areas perceived to have the hottest and coldest temperatures throughout the day. The average temperature selected by S. varius in the thermal gradient was 35.3 °C ± 2.60. Selected temperatures by individuals ranged from 31.5 °C to 39.3 °C. Preliminary data from mid-summer show that they only reach their preferred temperature for an average of 1.4 hours per day. The outdoor copper models show that they have the capability to reach their preferred temperature for about 8.5 hours per day. This suggests that thermoregulation to their preferred temperature is not the highest priority at this time of year. The identification of a species’ preferred temperature is crucial for understanding thermoregulatory patterns in the field. Examining how this endemic island species copes with rising temperatures in a rapidly-changing world can provide useful information toward conservation efforts and husbandry practices.
