Effect of Body Configuration on Perturbation Resistance Across Arboreal Lizard Species.

Abstract

Animals that inhabit high-risk habitats often exhibit morphological and behavioral adaptations to contend with environmental challenges. In arboreal (tree-based) habitats, such adaptations can include corrective behaviors, such as modification of body-limb angles, to avoid dislodgement by perturbations. This study evaluated shifts in limb and tail movements by three arboreal lizard species with different body configurations (variations of limb posture, body height, and tail prehensility) as they experienced simulations of unexpected arboreal perturbations. Animals were placed on a custom-built, laterally sliding perch apparatus, with trials filmed using high-speed video. Effects of different body configuration on restabilization performance were evaluated by comparing center of mass (CoM) displacement, limb angles, and tail behavior that occurred during the recovery from a sudden stoppage of perch movement. Results indicated that both body configuration and tail behavior influenced CoM displacement more than other kinematic factors. Across the three configurations that we compared, the sprawling, prehensile-tailed body configuration showed significantly larger CoM displacement compared to the upright, prehensile-tailed and the sprawling, non-prehensile-tailed configurations, especially when utilizing dynamic tail rotation as a stabilization behavior. These data indicate that a wide range of kinematic behaviors can be employed by arboreal lizards to ensure stability when subjected to potential dislodgement, but specific approaches, may contribute to superior performance for species with particular body designs, as seen with the use of dynamic tail rotation used by sprawling, prehensile-tailed species.