The continuous recording of the body temperature of European adder in summer

A continuous recording of body temperature of a light-coloured and black pregnant vipers in summer with iBDL loggers shows their lack of nocturnal activity. In cold mornings ablack viper warms up much faster than a light-coloured one, which gives it an advantage in achieving the optimal body temperature. The speed of the morning warming-up of snakes is higher than the speed of the evening cooling. The maximum body temperature of pregnant European vipers ranges from 37,1 ˚C to 38,2˚C. The high temperature level of a black adder may be achieved at relatively low ambient temperature, and that of a light-coloured one at the relatively high. The higher the temperature, the lower is its correspondence to the snakes’ body temperature and the strength of its influence on of this temperature. With the decrease in ambient temperature, the correspondence and the strength of the influence increases.