Meeting Abstract
Behavior plays a fundamental role in regulating the thermal environment experienced by an ectothermic animal. Animal speed and spatiotemporal patterns of environmental variation determine the temporal scale of thermoregulation. Slow animals cannot moderate quickly-fluctuating temperatures by moving between microclimates unless those microclimates are very close together. However, they may use predictable patterns of environmental fluctuation to thermoregulate. Snails are quintessentially slow animals. The marine intertidal snail Nucella ostrina is not only a slow walker, but a slow forager. In the intertidal zone, temperature fluctuations are rapid (minutes to hours), but tides limit the potential for thermal extremes to specific days of a two-week cycle. N. ostrina makes its prolonged foraging bouts to risky high shore areas only on the days of the tidal cycle that are predictably devoid of thermal extremes. We used observed snail foraging behavior, body temperature from physical thermal models, and thermal performance assays of righting response, to model the environment the snail actually experiences during spring/summer low tide exposure. We found performance of this species drops dramatically after a 2 h exposure above 30°C and mortality is high at 35°C. Our model showed a 60% or greater reduction in low-performance temperatures experienced by a migrating versus stationary snail. This reduction persisted when we considered temperatures 2°C higher as predicted by global climate change. This behavioral filter of environment greatly reduced the proportion of time N. ostrina was exposed to thermal risk. This snail is unlikely to be directly affected by thermal costs of climate change because it simply isn’t present in times and places where performance-reducing temperatures occur.
