General Research Interests
The research in my lab integrates several areas of biology to better understand how animals function in their environment. We work at the interface of ecophysiology and ecomechanics by combining comparative physiology, comparative biomechanics, functional morphology, ecology, and evolution. This broad approach facilitates a thorough understanding of animal movement in relation to ecological pressures. Several new research projects examine how animals are successful at moving and capturing prey in extreme environments, including the wave-swept intertidal, fast flowing streams, and hot deserts. See below for examples of recent projects.
- Muscle dynamics and biomechanics of vertebrate locomotion (see publications 1-3, 6, 14-16, 22, 25, 28-33, 36-39, & 41)
- The biomechanics and evolution of gecko locomotion (see publications 19, 22 & 27)
- Physiology, biomechanics and evolution of predator-prey interactions in fishes (see publications 6, 9-11, 26 & 35)
- Effects of exercise-induced fatigue on skeletal muscle mechanics and activation patterns (see publication 18)
- The neurobiology and biomechanics of tail autotomy in lizards (see publication 20, 34 & 40)
- Hydrodynamics and biomechanics of suction feeding in fishes (see publications 4, 5, 7, 8, 12, 13 & 24)
- Electromyography (EMG): This technique allows one to measure the electrical activity in a muscle using indwelling electrodes. I use this to quantify the intensity and timing of activation patterns during dynamic locomotion
- Sonomicrometry: This technique utilizes ultrasonic pulses between piezoelectric crystals to measure distances in real time. For example, I implant these into muscles to measure the changes in length along a fascicle.
- Aurora in situ/in vitro muscle lever system: I use this system to examine force-length and force-velocity properties of muscles. By combining this with in vivo measurements, I am able to determine how muscles operate in relation to their capabilities.
- Digital particle image velocimetry (DPIV): This is a modern computational technique that permits the visualization of fluid movement. I use this to determine flow patterns during suction feeding in fishes.
- High-speed digital video: I use a pair of Photron APX-RS cameras and a pair of Phantom Miro M110 cameras (capable of filming 250,000 images/second) to quantify three-dimensional high-speed movements during locomotion and prey capture.
- In vivo pressure recordings: By surgically implanting pressure transducers into the mouth (buccal) cavities of fishes, I quantify the pressure within the buccal cavity relative to the surrounding fluid during suction feeding in fishes.
- Force plates: I use a custom built force plate (from 6 axis force-torque sensors) to quantify the mechanics of terrestrial locomotion in birds and lizards. This involves inverse dynamics and center of mass mechanics, and I study animals from 3kg down to 2g.