Authors: Stark, Gavin; Levy, Ofir;Ma, Liang;Zeng, Zhi-Gao;Du, Wei-guo;

The availability of cool microhabitats in the desert is limited but critical for the ability of ectothermic species to perform behavioural thermoregulation. Although most studies focus on vegetation cover as a thermal shelter, we still lack a deep understanding of the importance of other microhabitats for thermoregulation, especially in hot and dry deserts where vegetation is scarce. We measured the preferred body temperature of lizards and recorded temperatures offered by different bushes and rocks of various sizes and we developed a biophysical model that simulates a thermoregulating lizard and calculates the percentage of microhabitat usage. Our empirical data suggest that large and medium rocks offer much cooler temperatures than bushes (by 9°C) and that the open microhabitat, bushes, and small rocks, are often too warm for lizards. Moreover, our simulation predicted that lizards should spend most of their activity time under medium and large rocks (~35%) than under bushes (~4%) or in the open (~25%), suggesting that rocks have a critical role as a refuge from high temperatures during the summer. Our research sheds light on the importance of medium-to-large rocks as an ecological resource, which may provide many animals protection from the extreme temperatures of the desert.