Field, selected body temperature and thermal tolerance of the syntopic lizards Phymaturus patagonicus and Liolaemus elongatus (Iguania: Liolaemidae)

Liolaemus elongatus and Phymaturus patagonicus are viviparous lizards syntopic in the rock promontories of the arid Patagonia exposed to seasonal extremes, short activity seasons and long submergence periods. L. elongatus is a slender lizard mainly heliothermic, which occupies a variety of microhabitats and has a widespread distribution. P. patagonicus, instead is a tigmotherm and flat body lizard which lives only in the clefts of rock promontories and has a restricted distribution to the north west Patagonia. In the present work, the field and selected body temperature and their thermal tolerance are explored. L. elongatus shows a higher plasticity than P. patagonicus in the use of the microhabitats, the heat acquisition, and the activity timetables. However both species show low field and selected body temperature compared to most lizards (30 °C). These results reinforce the hypothesis between reproduction and body temperature postulated by previous works on reproductive biology of both species.