Meeting Abstract
Climate change can alter species’ habitat and dietary requirements and can ultimately modify species’ optimal foraging strategies. Optimal foraging theory suggests that animals adjust foraging preferences to maximize gains in energy per unit of time. The eastern red-backed salamander (Plethodon cinereus) preys on a wide variety of forest floor invertebrates and, as a lungless ectotherm, is highly dependent upon on cool and moist environments for gas exchange. Previous research describes the diet of P. cinereus, but does not consider the interaction between temperature and P. cinereus dietary preference. This study examined the impact of temperature on the dietary preferences of P. cinereus and tested whether foraging strategies affect body condition, a proxy for overall fitness. To investigate these questions, we offered three prey types to salamanders at 10 and 20°C. Prey types included crickets, mealworms, and legless crickets, which differ in fat content and aversion. We presented all prey types to each salamander for 48 hours and recorded the number of each prey type eaten every 12 hours. We repeated this procedure three times, recording body mass at the beginning and end of each trial to calculate change in body condition. Ectothermic species’ fitness is maximized at temperatures just below thermal optimum for performance, allowing for more selective foraging. Thus, we predicted that P. cinereus prefers less aversive, high fat prey types at 10°C and are less selective at 20°C. If P. cinereus uses optimal foraging strategy to maximize energy gains at each trial temperature, we predicted that salamanders will maintain or increase body mass. Our results will motivate forest floor community and food web models to contribute to successful forest ecosystem conservation efforts in response to climate change.
