Kinematics of Terrestrial Snake Locomotion

Abstract

The lateral undulatory, sidewinding and concertina modes of limbless terrestrial locomotion were analyzed from cinematographic films of five species of snakes and one amphisbaenian crawling on a variety of substrates. For single points on each animal, graphs of V, (overall velocity), V, (longitudinal component) and V, (lateral component) vs time were used to characterize locomotor modes and to detect their simultaneous use. Only concertina locomotion was used by the amphisbaenian Rhineura floridana. While performing lateral undulation, the constricting colubrid snake Elaphe obsoleta did not attain a maximum mean V, as great as that of Nerodia fasciata, a nonconstricting colubrid. Concertina locomotion is described for the snakes Acrochordus javanicus and N. fasciata. Sidewinding is described for N.fasciata, Cerberus rynchops and Crotalus cerastes. Cerberus rynchops moving on sand combined sidewinding with lateral undulation. The relation between V, and frequency of movement is described and compared among each of the terrestrial modes and with aquatic lateral undulation.