NO TRADE-OFF BETWEEN SPRINTING AND CLIMBING IN 2 POPULATIONS OF THE LIZARD PODARCIS-HISPANICA (REPTILIA, LACERTIDAE)

Biomechanical reflections suggest that lizards that have specialized i n running should differ in parts of their morphological design from li zards that have specialized in climbing. Moreover, adaptation in one d irection may conflict with performance in the other. We tested this as sumed trade-off by measuring climbing and running performance in two s ubspecies of the Mediterranean lizard Podarcis hispanica. One subspeci es, P. h. atrata, inhabits a number of small islets near the Spanish c oast. It is mainly ground dwelling. The other subspecies, ti h. hispan ica, was sampled on the mainland of Spain. It frequently occupies vert ical elements within its habitat. Our data do not support the notion o f a trade-off between both types of locomotion. Individuals of P. h. h ispanica both run and climb faster than those of P. h. atrata. There i s no difference between subspecies in ability to cling onto tilted sub strates. Predictions on the morphology of both subspecies, inspired by biomechanical arguments, are not supported by our measurements. (C) 1 997 The Linnean Society of London.