Meeting Abstract

69.4  Tuesday, Jan. 6  Arboreal habitat structure affects the performance and modes of locomotion of corn snakes (Elaphe guttata) ASTLEY, H.C.*; JAYNE, B.C.; Brown University; University of Cincinnati henry_astley@brown.edu

Arboreal environments pose many functional challenges for animal locomotion including fitting within narrow spaces, balancing on cylindrical surfaces, moving on inclines, and negotiating obstacles. Many species of snakes are arboreal and their elongate, flexible bodies appear well-suited to meet many of these demands, but the effects of arboreal habitat structure on snake locomotion are not well understood. We examined the effects of surface shape (cylinder vs. rectangular tunnel), surface width, incline, and a row of pegs on the performance and modes of locomotion of adult corn snakes (Elaphe guttata). The addition of pegs allowed snakes to move on the widest and steepest surfaces that were impassable without pegs. Tunnels also allowed snakes to move on steeper inclines than cylinders with similar widths. The mode of locomotion changed with habitat structure. On surfaces without pegs, most snakes used two variants of concertina locomotion but always moved downhill using a controlled slide. Snakes used lateral undulation on most surfaces with pegs. The detrimental effects of increased uphill incline were greater than those of increased surface width on maximal velocity. Snakes moved faster in tunnels than on cylinders regardless of whether pegs were present. Depending on surface width, the addition of pegs to horizontal cylinders and tunnels resulted in 8 to 24-fold and 1.3 to 3.1-fold increases in speed, respectively. Narrower bare cylinders enhanced snake locomotor performance, contrary to the detrimental effects of decreased width on the speed of most arboreal limbed animals.