Meeting Abstract
Organisms must allocate resources to support different performance traits. Since resources are finite and the conditions that optimize one trait may decrease performance in another, the prioritization of certain traits may come at the cost of others. The performance traits that an organism prioritizes allocation toward determine their life history strategy. For ectotherms, different performance traits like locomotion and fecundity are optimized at different body temperatures. Ectotherms behaviorally thermoregulate to select suitable microhabitats that optimize combinations of metabolic and performance traits. Thus, we hypothesized that life history strategies determine ectotherm thermal preferences. However, thermal preferences are not fixed. In response to starvation reductions in thermal preference commonly occur to conserve energy and the extent to which life history strategies determine the impact of starvation on thermal preference is unknown. Wing-dimorphic crickets have either long (LW) or short (SW) wings and specialize in dispersal or reproduction, respectively. Crickets were placed in a thermal gradient of 15-50 C° and the temperatures at which they settled 30, 40, and 50 minutes after placement were recorded. This experiment was conducted both in the field with freshly caught individuals and in the lab with crickets reared under common conditions. In both the lab and field, LWs preferred significantly higher temperatures compared to the SWs. Under starved conditions crickets preferred a cooler environment and morph differences disappeared. Together these findings suggest that life history strategy determines thermal preferences, but when resources are sparse, energy conservation is prioritized at the cost of performance.
