Meeting Abstract
For many ectotherms, temperature has a profound effect on performance, such as for the sprint speeds of lizards. However, elastic-recoil mechanisms have allowed other ectotherms to partially circumvent temperature dependence, such as the tongue-projection mechanisms of some salamanders and chameleons. In one paper, pre-strike muscle activation patterns in a viper indicated that striking is driven largely by elastic recoil of the muscle-tendon complex. With elastic-recoil mechanisms being partially independent of temperature, we would expect strike performance in snakes to have low tempen that temperature significantly affects strike performance. Here, we set out to tesrature-dependence under the elastic-recoil hypothesis. However, work on another viper has showt the effects of temperature on defensive strike performance in adult western ratsnakes (Pantherophis obsoletus). To do this, we tested each snake at 5 body temperatures (15–35°C) and recorded 3–8 defensive strikes at each temperature using a high-speed camera (250 fps) and Tracker 4.87 software. We analyzed peak performance values for each of four strike variables: maximum strike distance, minimum strike duration, maximum strike velocity, and maximum strike acceleration. We analyzed each strike variable as a dependent variable and the temperature category as the independent variable (repeated measure) in order to characterize the effects of body temperature on strike performance. Changes in temperature significantly affected strike performance in ratsnakes with reduced strike performance at lower temperatures and the highest strike performance at 30°C. The significant and moderate temperature dependence in our results indicates that elastic recoil contributes only mildly, if at all, to strike performance in snakes.
