Meeting Abstract

P3.70  Monday, Jan. 6 15:30  Mathematical model of the dynamic energy budget of the green anole lizard (Anolis carolinensis) QUINN, MM*; BUSH, JM; DILL, AK; BALREIRA, EC; JOHNSON, MA; Trinity University mquinn2@trinity.edu

All animals must allocate the energy they obtain from their food among the processes that support their survival. While different animal species use energy in different ways, few studies have yet examined energy allocation in reptiles. In this study, we developed a mathematical model of energy use in the green anole lizard, Anolis carolinensis, to determine the amount of energy used for basic metabolism and growth in a laboratory setting. To build this model, we first quantified the extent of available energy (defined as energy from food, minus energy lost through excretion). We collected empirical data by housing 19 adult male lizards in the laboratory for 40 days, feeding each lizard 3-5 crickets of known mass each day. Every third day, we measured each lizard’s snout-vent length (SVL), mass, and excreta. We determined the energy in the crickets and excreta via bomb calorimetry, and we used a respirometer to measure each lizard’s resting metabolic rate (RMR), a measurement of the energy required for basic maintenance. Using these data, we developed several alternative models, combining different functions of metabolism and growth and using linear and nonlinear regression to create a dynamic energy budget. We only considered biologically reasonable models, which we defined as those that included a positive relationship between available energy and growth, and showed growth as a decreasing function of SVL. Our best model used an approximation for relative growth as a decreasing nonlinear function of SVL and did not include an estimate of metabolism, indicating that energy spent on simple metabolic processes only utilized a very small amount of the lizards’ overall energy budget.