Meeting Abstract

P1.191  Friday, Jan. 4  How do flying snakes land on a branch? Kinematics and impact forces of landing in Chrysopelea ornata TWYMAN, CA*; HALES, K; SOCHA, JJ; Virginia Tech; Virginia Tech; Virginia Tech catwyman@vt.edu

For vertebrate gliders, becoming airborne can be as simple as jumping, but landing on a hard substrate such as a tree trunk may entail a high risk of injury. At the end of a glide trajectory, gliders such as flying squirrels can maneuver to a favorable body position that allows for a foot-first contact upon landing, but snakes lack this capability. Here we address the question, how do gliders with no appendages land safely on an arboreal substrate? When landing on the ground, flying snakes (genus Chrysopelea) tend to land tail-first, which aids in decreasing impact forces by increasing the duration of the landing. In preliminary recordings of snake landings onto tree branches, some snakes contacted the branch near the mid-body, and then the anterior and posterior sections wrapped partly around the branch, perhaps carried forward from the momentum of the trajectory. We hypothesize that, when landing on a cylindrical substrate, flying snakes maximize the percentage of body that wraps around the cylinder, resulting in longer landing durations and smaller impact forces. Using body markers and three high-speed cameras, we recorded the landing kinematics of Chrysopelea ornata to determine landing duration and degree of branch-wrapping of the body. Additionally, we instrumented the horizontal landing cylinder with strain gauges to measure the forces involved in landing. This is the first study to address limbless landing, lending insight into a novel use of the axial body as a locomotor ‘brake’.