Comparative thermal ecology of the sympatric lizards Podarcis tiliguerta and Podarcis sicula

We studied field body temperatures (T sub(b)) in sympatric populations of the Mediterranean lizard species Podarcis tiliguerta) and P. sicula . Both species have identical activity rhythms, experience highly similar ambient conditions and maintain body temperatures around identical mean values. However, P. sicula regulates its T sub(b) more precisely than P. tiliguerta), as indicated by the lower value of the regression slope of T sub(b) on air and substrate temperatures, the lower variance in T sub(b)s, and the absence of diurnal variation in T sub(b)s in the former species. Available data of selected T sub(b)s suggest that both species have highly similar thermal preferences. Both species differ in microhabitat use: P. tiliguerta) was almost exclusively seen on rocks and stone-walls, often at perch heights >50 cm and at short distances to patches of shade; P. sicula basked on rocky surfaces but foraged on ground in open meadows, often at distances of >5 m to deep shade.