As soon as the air temperature rises above 10°C in spring, we open the burrows in the terrariums at the Viper Centre and begin weighing the snakes that hibernate underground during the winter. We check and weigh each of the more than 1,400 vipers living in the centre to determine how their condition has changed during the five to six months they have spent underground. Based on measurement data from previous years, we have observed minimal weight loss after hibernation, and in many cases the snakes do not lose any weight at all during the period between the start of hibernation and spring awakening. During this time, they rest in a hibernating state without feeding deep in the burrows.
It is crucial to provide drinking water for the snakes in the terrariums as the males drink immediately after waking up from hibernation. In the wild, the availability of water also determines when the first males emerge. After drinking, the snakes’ shedding cycle begins, lasting 2–3 weeks. The air temperature is still lower than ideal at this time, but the snakes are able to reach their ideal body temperature with the help of direct or filtered sunlight. This enables them to reach a body temperature of up to 20–25 °C, compared to the air temperature of 10–15 °C.
Due to global warming, as well as this year’s mild winter and spring, the first specimens appeared on the surface at the end of January. On 30 January, while searching for a snake equipped with a radiotag, we found not only that particular snake, but also a previously released adult male enjoying the mild late-winter weather and the warmth of the sun.
