9321458 Full This project addresses a question of major interest to physiological ecologists: does physiological capacity reflect performance in nature? Precise measurements of locomotion in nature will test predictions based on laboratory measurements of the energetics underlying endurance capacity in a nocturnal lizard, the banded gecko (Coleonyx variegatus). Nocturnal lizards represent a substantial evolutionary shift in environment. Nocturnality imposes a thermal handicap, which constrains endurance capacity to submaximal levels. Nocturnal geckos have evolved excellent fuel economy, which partially offsets the thermal handicap. In this dissertation research project, Mr. Autumn will use infrared video motion analysis to obtain quantitative measurements of frequency, speed, and duration of locomotion of banded geckos in the field. He will test the hypothesis that natural performance loads are limited by nocturnality, yet exceed the capacity of comparable diurnal lizards. This project will complete a picture that links (1) effects of evolution of environment on physiological capacity with (2) effects of evolution of physiological capacity on performance in nature. ***
