Effects of habitat structure on arboreal locomotion of corn snakes (Elaphe guttata)

Arboreal environments pose many functional challenges for animal locomotion including fitting within narrow spaces, balancing on cylindrical surfaces, moving on inclines, and negotiating obstacles. In spite of numerous arboreal species and an elongate, flexible bodies well-suited to meet these demands, the arboreal locomotion of snakes is not well understood. We examined the effects of two surface shapes (cylinder vs. rectangular tunnel), seven surface widths, five inclines, and pegs on the performance and modes of locomotion of adult corn snakes. Snakes could traverse steeper inclines with the addition of pegs, with decreased surface width, and for tunnels rather than cylinders. Pegs allowed snakes to move on all tested surfaces. On surfaces without pegs, most snakes used two variants of concertina locomotion, but snakes used lateral undulation on most surfaces with pegs. Maximal velocity was minimally affected by surface width, and decreased on perches compared to tunnels and with increased uphill incline.