Thermal biology of Liolaemus scapularis (Iguania:Liolaemidae) from argentinian northwest  

SALVA, G; ROBLES, CI; TULLI, MARÍA JOSÉ

JOURNAL OF THERMAL BIOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2021 vol. 98

0306-4565

Thermal traits knowledge is elemental to forecasting the impacts of environmental change on lizard diversity.Daily and seasonal environmental temperature fluctuations are amplified in desert and semi-desert species. Asectotherms, they can ameliorate physiological constrains through behavioral thermoregulation. Herein, weexplored the thermal biology and behavioral related aspects of the endangered sand lizard Liolaemus scapularisand compared it between austral spring and summer seasons. The study was carried out in a north sector ofMedanos de Cafayate in the SW of Salta province, Argentina. Mean field-body temperature (Tb) of L. scapulariswas 35.72 ◦C ranging from 29.10 to 41.10 ◦C. Regression analyzes showed that substrate temperature (Ts) wasthe parameter that best explained the variability of the Tb. Body temperature in spring was only positivelyrelated to Ts, whereas in summer the Tb was positively related to air temperature (Ta). Despite GLMs indicatedthat the Tb of L. scapularis result statistically unchanged through seasons sampled and sexes, microenvironmental temperatures were different for males and females between sampled seasons. The behavioralthermoregulation trait assessed, sun exposure, revealed that the use of patches with different sun input variedwith temperature parameters and between seasons. This behavioral trait seems to have a crucial role in thethermal strategy of these lizards in order to maintain an optimal homeostatic state avoiding overheating; still theTb recorded for the studied population places Liolaemus scapularis in the upper range for the genus. Our resultssuggest that the species is an active thermoregulator with a hit gain through sand conduction mainly, a relevantshuttling behavior and seasonal intraspecific shifts.