Influence of the environmental temperature regime on the body temperature of Lacerta agilis Linnaeus, 1758 (Lacertidae, Reptilia) in local populations of the Khoper river floodplain in spring

An analysis was made of the influence of the biotope temperature regime on the body temperature of Lacerta agilis in local populations of the floodplain of the middle reaches of the Khoper river (Saratov region). The rectal body temperature in active L. agilis out-side their shelters was shown to be 18.3–35.1°С and 18.2–34.8°С for males and females, respectively. The rectal temperature of L. agilis males and females in the spring period does not differ significantly. The optimal body temperature of L. agilis, which the activity of individuals is observed at, should be considered as 24.2–33.0°C.