Movie 2.

Corn snake in lateral view within a tunnel made of PVC boards showing two trials. In the first trial both prior to and while crossing the wedge (sloped at 8°) the corn snake performs concertina locomotion. Following this trial, prior to the wedge (sloped at 30°), the corn snake performs concertina locomotion and transitions to vertical undulations after encountering the wedge.

Generation of propulsive force via vertical undulations in snakes

Derek J. Jurestovsky, Logan R. Usher, and Henry C. Astley

Journal of Experimental Biology 2021. 224:None-None; doi: 10.1242/jeb.239020