Meeting Abstract
Size plays a major role in how organisms move through their environments. Children negotiate obstacles differently than adults do, and they also move their short legs at a much higher frequency to achieve the same speeds as walking adults. Many animals face these sorts of challenges as they grow. Controlling for size, morphology also matters for locomotion. We studied how body size and shape affect sidewinding locomotion in the rattlesnake Crotalus cerastes. We collected various morphological measurements and high-speed video for 73 sidewinders ranging in size from 8 to 272 g. Previously, we demonstrated that morphology scales isometrically, meaning young sidewinders are essentially miniature adults. New analyses show that the shape of the wave formed by the body during sidewinding also shows geometric similarity across sizes, but that other kinematic variables, such as the height lifted or duty factor for individual points along the body, scale with negative allometry. Differences in body shape such as elongation ratio or tapering affect kinematic variables such as acceleration, wavelength, and wave amplitude. These size and shape effects could play a role in habitat use as snakes grow, and they could also contribute to intraspecific behavioral differences.
