Georgia Undergraduate Research Conference (2014-2015)

Consequences of Complex Environments: Temperature and Energy Intake Interact to Influence Growth and Metabolism

Concourse/Atrium

The field of comparative physiology has a rich history of elegantly examining the effects of individual environmental factors on performance traits linked to fitness (e.g., thermal performance curves for growth or locomotion). However, animals live in complex environments wherein multiple environmental factors vary simultaneously. Thus, we investigated the independent and interactive effects of temperature and energy intake on the growth and metabolism of juvenile corn snakes (Pantherophis guttatus, Linnaeus) in the context of global climate change (GCC). Unlike previous studies that imposed constant or fluctuating temperature regimes on animals, we manipulated the availability of preferred thermal microclimates (control vs. warmer-than-preferred regimes) for eight weeks and allowed snakes to behaviorally thermoregulate among microclimates. By also controlling for energy intake, we demonstrate an interactive effect of temperature and energy on growth— GCC-relevant temperature shifts had no effect on snakes’ growth when energy intake was low and a positive effect on growth when energy intake was high. Temperature and energy also interactively influenced metabolic rate—snakes in the warmer temperature regime exhibited reduced metabolic rate (O₂ consumption rate at 25°C and 30°C) if they had relatively high-energy intake. Although we advocate for continued investigation into the effects of complex environments on other traits, our results indicate that GCC may actually benefit important life history traits and that metabolic shifts may underlie thermal acclimation.