Meeting Abstract
Climbing has evolved multiple times in family Plethodontidae. In the absence of specialized toe pads or claws common to other scansorial organisms, salamanders climb on rough and smooth surfaces through either gripping via the toes, adhesion of the ventral skin surface, and in some species, by suction. Clinging and climbing performance on a smooth acrylic surface was examined in multiple climbing and non-climbing species within Plethodontidae to determine the maximum angle at which performance was maintained. Functional adhesive surface area and climbing kinematics during locomotion at various angles were quantified with an edge-illuminated acrylic sheet using frustrated total internal reflection. Significant variation in climbing ability on smooth surfaces was found among species, with the most adept climbing species performing comparably to tree frogs that possess adhesive toe pads. Variation in climbing performance could be accounted for by behavioral adaptations to enhance movement on smooth, inclined, and vertical surfaces or by species-specific attachment mechanisms, such as increased skin stickiness or suction. Maintenance of climbing performance over a wide range of body masses was observed in some scansorial species; in many non-climbing species, climbing ability was strongly limited by functional surface area in relation to body mass. Variation in the minimum relative surface area necessary to maintain attachment at high angles suggests species-specific attachment mechanisms benefit climbing species.
