干旱区生态环境知识资源中心

Field active body temperatures (T-b) and operative temperatures (T-e) were assessed in a population of Uromastyx aegyptia microlepis at Mahazat as-Sayd Protected Area, Saudi Arabia. In summer T-b ranged between 23.2 and 47.2 degrees C, in winter between 23.0 and 451 degrees C and in spring between 25.5 and 45.9 degrees C. There is a significant difference between respective T-b and T-e distributions which suggests that U. a. microlepis is an active thermoregulator. Above ground activity is very variable between seasons, with the highest activity level in spring. In winter the animals showed an unimodal activity profile. In spring and summer the lizards exhibit bimodal activity profiles with afternoon activity being generally lower than morning activity levels. Species distribution models were calculated to estimate the future impact of global warming on this taxon. Estimates on the basis of temperature data suggest that the range size on the Arabian Peninsula might be stable but with a remarkable decrease of environmental suitability of up to 70-80%. Based on a synthesis of thermo-ecological data and species distribution models we consider climate warming as a potential threat to the survival of the species. (C) 2011 Elsevier Ltd. All rights reserved.