Thermal ecology of three coexistent desert lizards: Implications for habitat divergence and thermal vulnerability.
How ectotherms exploit thermal resources has important implications for their habitat utilization and thermal vulnerability to climate warming. To address this issue, we investigated thermal relations of three sympatric lizard species (Eremias argus, Eremias multiocellata, and Phrynocephalus przewalskii) in the desert steppe of Inner Mongolia, China. We determined the thermoregulatory behavior, body temperature (Tb), operative temperature (Te), selected body temperature (Tsel), and critical thermal maximum (CTmax) of adult lizards. Based on these physiological parameters, we quantified the accuracy and effectiveness of thermoregulation as well as thermal-safety margin for these species. The three species were accurate and effective thermoregulators. The P. przewalskii preferred open habitats, and had a higher Tbthan the two Eremias lizards, which preferred shade habitats and shuttled more frequently between the shade and sun. This indicated that the three sympatric lizards have different thermoregulatory behavior and thermal physiology, which might facilitate their coexistence in the desert steppe ecosystem. In addition, the P. przewalskii had higher Tseland CTmax, and a wider thermal-safety margin than the two Eremias lizards, suggesting that the two Eremias lizards would be more vulnerable to climate warming than P. przewalskii.
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China.|University of Chinese Academy of Sciences, Beijing, People's Republic of China.
Shu-Ran
SR
Li
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China.|University of Chinese Academy of Sciences, Beijing, People's Republic of China.
Yang
Y
Wang
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China.|University of Chinese Academy of Sciences, Beijing, People's Republic of China.
Liang
L
Ma
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China.
Zhi-Gao
ZG
Zeng
College of Life Sciences, Inner Mongolia Normal University, Hohhot, 010022, Inner Mongolia, People's Republic of China.
Jun-Huai
JH
Bi
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China. duweiguo@ioz.ac.cn.
Wei-Guo
WG
Du
D000064:Acclimatization; D000818:Animals; D001522:Behavior, Animal; D001833:Body Temperature Regulation; D003889:Desert Climate; D017753:Ecosystem; D057232:Global Warming; D008116:Lizards / Q000145:classification / Q000502:physiology*; D013045:Species Specificity; D013472:Sunlight; D013997:Time Factors
Climate warming; Desert; Ecological divergence; Reptiles; Thermoregulation