Balancing Acts: Exploring trade-offs in climbing snake locomotion

Arboreal environments are difficult to traverse due to diverse structures varying in their diameter, stiffness, and surface roughness. Some snake species contend well with these challenges, contorting their limbless bodies in ways that that enable them to traverse vertical surfaces, even those with low or no curvature. To investigate climbing strategies used by corn snakes (Pantherophis guttatus), we created an experimental apparatus consisting of a smooth, vertical wall. Evenly spaced force-sensing pegs protrude from the wall and serve as the only useable features available for the generation of propulsive forces. Simultaneous measurements of the snakes’ kinematics and dynamics reveal that they modify their waveforms to match body bends with the locations of differently spaced pegs, and that their ability to produce lateral forces diminishes when body bends are spaced further apart. To simulate the effects of different movement patterns, we developed a computational model and used geometric calculations to explore the space of allowed postures. By analyzing the speed and stability provided by different body shapes, we investigate trade-offs to predict effective movement patterns and compare the predictions with experimental observations. Future work will explore the effect of species specialization on the success of climbing.