BERGMANN, P.J.**; IRSCHICK, D.J.; Tulane University; Tulane University: The temperature-dependence of clinging and sprinting ability in day geckos.

We studied the clinging ability and sprinting velocity, acceleration, deceleration, and power output between 15&degC and 35&degC in the diurnal gecko, Phelsuma dubia. We measured clinging performance of the front limbs by dragging lizards across a force plate, and unsteady-state, accelerating sprinting performance using high speed video recordings of lizards running up a vertical race track. Our findings indicate that temperature does not affect these performance measures uniformly. Clinging ability is highly variable across temperatures and unaffected by temperature. In contrast, all velocity, acceleration, deceleration, and power output during unsteady-state sprinting are all enhanced by increases in temperature across the range studied. Power output is more sensitive to temperature than the other sprinting performance measures, increasing almost 4 fold between 15&degC and 35&degC. Increases in running speed are modulated by both increases in stride length and frequency. However, duty factor is unchanged across the temperature range. Our findings for sprinting parameters match those expected from the literature. However, a lack of temperature-dependence in clinging ability is surprising, and suggests that maximal clinging ability, as measured, is primarily dependent on passive processes, such as Van Der Waals forces.