Meeting Abstract
P2.12 Saturday, Jan. 5 What contributes to variability in behavioral thermoregulation? STAHLSCHMIDT, ZR*; ADAMO, SA; Dalhousie University; Dalhousie University zrs@dal.ca
Because many life history traits are influenced by temperature, behavioral thermoregulation can significantly improve animal fitness. However, considerable inter-individual variation in preferred body temperature (Tpref) persists within species. Thus, to our knowledge, we used the most comprehensive experimental approach to date to understand what contributes to Tpref variability. Specifically we used the adult Texas field cricket (Gryllus texensis) and manipulative approaches to clarify the independent and interactive effects of sex, adult stage (young virgin or older mated), morphology (e.g., body size and condition), fecundity, nutritional state (e.g., acute or chronic food limitation), and immune challenge on Tpref. We demonstrate that environmental variables (food availability and immunogen exposure), adult stage, and morphological traits exhibit complex interactions among each other and with regard to behavioral thermoregulation. Although we successfully manipulated body condition and reproduction, our results failed to support dogmatic predictions about the role of these two variables in Tpref. Males and more robust (high body condition) females exhibited low Tpref. Crickets that were not food limited and those that were larger, heavier, and more robust exhibited a more variable Tpref. Adult stage and fecundity (oviposition rate) did not affect Tpref. Previous research demonstrates warm temperatures are beneficial to crickets (e.g., improved current reproduction). However, our results suggest maintaining a high, stable body temperature may be offset by considerable ecological costs (e.g., increased predation risk) or costs conferred to offspring (e.g., reduced hatching success) that warrant further consideration. We provide evidence that understanding a given behavior requires examining the independent and interactive roles played by several important life history traits.
