The Herpetological Journal

pp. 239-244

Authors: Zaida Ortega, Abraham Mencía & Valentín Pérez-Mellado

Abstract: We studied the thermal ecology of the montane Iberian rock lizard, Iberolacerta monticola, in the western area of its distribution at the Serra da Estrela (Portugal). We calculated the precision of thermoregulation and the indices of thermal quality of the habitat, and accuracy and effectiveness of thermoregulation. To complete the study of the thermal ecology, we assessed the
relationships between body and environmental temperatures, and we described the thermal and spatial heterogeneity of the habitat. Our results indicate that the Iberian rock lizard is a cold-specialist, with a preferred temperature range between 29.80 and 31.60 °C. Thus, precision of thermoregulation is 1.8 °C, which is a normal range in thermal specialists, like other species of the genus Iberolacerta. This result is important because being thermal specialists and living in mountaintops make Iberian mountain lizards particularly vulnerable to global warming. The habitat of I. monticola at the Serra da Estrela is formed of microhabitats offering different operative temperatures, which allows lizards to select the most suitable for thermoregulation at any time of the day. Iberian rock lizards achieve an effectiveness of thermoregulation of 0.86, thanks to careful thermoregulatory behaviour. Rocky microhabitats occupy more than 50% of its habitat, so is probable that lizards are selecting rocks to warm themselves faster, minimising the costs of thermoregulation. A possible thigmothermic component of this kind would be unique among the species of Iberolacerta.

Keywords: thermoregulation, cold-specialist, global warming, lizard, mountains, Iberolacerta monticola, Lacertidae, thigmothermy