Meeting Abstract
Temperature has a substantial effect on both the physiology and behavior of ectothermic animals such as lizards. The Italian Wall Lizard (Podarcis sicula) is a widely introduced species that has demonstrated remarkable adaptability when introduced to new regions. We examined the thermal tolerances and preferred temperature of 28 P. sicula collected from an introduced population in California, USA. Critical thermal minimum (CTmin) and critical thermal maximum (CTmax) were determined as the temperatures at which the lizards lost their righting ability. Preferred temperature (Tpref) was determined using a linear thermal gradient. We compared the thermal tolerances and preferred temperatures of juveniles (N=12), adult females (N=7), and adult males (N=9). Adult females had a significantly wider thermal breadth (CTmax – CTmin) compared to adult males and juveniles (P<0.001). Adults of both sexes were able to tolerate warmer temperatures than juveniles (P<0.001), and adult females were better able to tolerate colder temperatures (P<0.001). Interestingly, there was no significant difference among groups for preferred temperature (P=0.861). This implies that thermal tolerance, a physiological characteristic, varies with age and gender for this population, whereas thermal preference, a behavioral characteristic, does not. Future work will compare the thermal tolerances and preferences of this population to those of a New York population, to examine whether these parameters shift with adaptation to different climates.
