Variability of thermoregulation parameters of the common viper

Abstract

The results of processing the data of continuous recording of body temperature using loggers obtained with the enclosure keeping 23 individuals of the common viper Vipera berus L. in Karelia (62.068310°N, 33.958824°E) are presented. Nine temperature characteristics, subdivided into 2 groups, were quantitatively evaluated – thermoecological, describing the dependence of the course of the viper’s body temperatures on the heat flux of the medium, and thermophysiological, stable parameters of thermoregulation. The factors that determine the variability of temperature characteristics are considered: time of day, weather conditions, morphometric indicators of an individual. A wide individual variability of thermoecological indicators and low variability of thermophysiological indicators were revealed, which was not associated with significant differences in different individuals. The parameter “maximum voluntary temperature”, which characterizes body temperature while avoiding overheating, is the closest to the physiological parameter of thermoregulation; obtaining such data is a very laborious process associated with deciphering the snake’s behavior from video recordings. An indicator that gives close values to the maximum voluntary temperature, which has a very simple calculation algorithm – “median active temperature (for a sample of temperatures above 30°C)”; however, it requires a volumetric series of continuously recorded temperature records for analysis. An accurate, statistically robust “maximum typical temperature” parameter gives an idea of the true maximum temperature characteristic of a species, but has a complex calculation method. These thermophysiological parameters are recommended to be used for intrapopulation and interspecies comparisons.