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Meeting Abstract

P3-134   -   Thermoregulation and Water Loss in Podarcis muralis (Common Wall Lizard) Spears, S*; Pettit, C; Berkowitz, S; Collier, S; Colwell, C; Livingston, E; McQueen, W; Vaughn, PL; Leos Barajas, V; Gangloff, EJ; Ohio Wesleyan University; University of Toronto

Climate change is progressing, not only warming the environment, but altering precipitation and climate patterns. The ability of ectotherms to effectively thermoregulate in changing environments is dependent not only on temperature, but on other abiotic factors, such as wind. Wind reduces both body and substrate temperatures and impacts water loss. Yet, the impacts of wind on thermoregulation remain largely unexplored. To study the effects of wind on thermoregulation, we first collected field data to assess whether body temperatures and hydration status of active animals were influenced by wind speed in populations of the common wall lizard (Podarcis muralis) in Cincinnati, Ohio, USA. We then conducted an experiment in the lab to test the effect of wind speed on thermal preferences and thermoregulatory behavior. In arenas with a gradient of 20-55°, we conducted 2-hour thermal preference trials with lizards (N = 12) under conditions of wind and no wind. Using a thermal imaging camera, we recorded body temperature at 30-second intervals and continuously recorded movements using a digital camera. After a 12-day waiting period, we then conducted a second trial with the opposite wind treatment. We extracted traditional metrics of thermoregulatory behavior, including preferred temperature and voluntary thermal maxima/minima, and quantified hydration status with water loss and hematocrit levels (ratio of red blood cells to blood volume). Additionally, we utilized hidden Markov statistical models to describe thermoregulatory movement patterns. We predicted that wind would constrain thermoregulation and P. muralis would prefer the cooler side of the windy gradient to reduce their water loss. Our combination of novel statistical approaches to movement patterns and traditional metrics of thermoregulation provide insight as to how P. muralis are affected by interacting environmental factors.