Meeting Abstract

P1.166  Monday, Jan. 4  Perch diameter and secondary branching have interactive effects on the locomotion of anole lizards JONES, Z.M.**; JAYNE, B.C.; University of Cincinnati, Ohio joneszm@mail.uc.edu

Several aspects of arboreal habitat structure such as the diameter, incline and the density of branches create challenges for the locomotion of animals, and arboreal lizards in the genus Anolis have been a model system for studying correlations between locomotor performance, habitat structure, morphology, and behavior. In natural vegetation decreased branch diameter is correlated with an increased density of branches. However, unlike the well-documented detrimental effects of decreased perch diameter on sprinting speeds of long-limbed anoles, the effects of this aspect of habitat structure are unknown for anoles and nearly all other arboreal animals. Thus, we tested the locomotor performance of Anolis carolinensis and A. sagrei running on cylinders with diameters ranging from 1 to 10 cm, and we placed pegs at 10-cm intervals along the top center of these perches to simulate and determine how secondary branches may interfere with locomotion. The lizards preferred to run along the top of the cylinders without pegs. However, on smaller diameters, pegs interfered with this, and the time to travel a fixed distance nearly doubled with the addition of pegs because the lizards paused more and were slower while they were running. The magnitudes of some of these detrimental effects of pegs on speed exceeded some of those for decreased diameter. However, pegs on the 10-cm diameter perch barely affected speed, and the speeds on the 10-cm perch with pegs commonly exceeded those of the smaller diameter perches lacking pegs. Our results suggest that in addition to selecting large perch diameters in natural vegetation for their direct benefits on locomotor performance, an added benefit may be to facilitate detouring around secondary branches with little adverse effect on maximum speed.