Winter is a time in nature that many animals have to survive in difficult conditions. Food is scarce, temperatures are dropping, and it costs them a lot of energy to keep their bodies warm. Migratory species leave for the winter to countries where there is enough food and temperatures are higher than in our country. Most of our bats use the safety and stable environment of caves in winter, where temperature and humidity do not fluctuate significantly in winter. Here they hibernate (= true hibernation with a decrease in heart rate and body temperature) until spring, when the temperature rises and their food, which is insects, is available again.
In the winter months, a regular census of bats takes place in the Veľká Fatra National Park at selected wintering grounds. Information on the abundance and occurrence of species is important in evaluating abundance, but especially for capturing trends in individual species. The most numerous species are the great bat (Myotis myotis) and the lesser horseshoe bat (Rhinolophus hipposideros), we also found the presence of grey eared bats, black eared bats, water bats, Brandt’s bats, variegated evening primroses, northern evening primroses, late bats, eastern bats, and greater horseshoe bats. In addition to bats, the caves are also used by spotted salamanders (Salamandra salamandra), various insects and spiders during the winter.
Caves in winter are a vital refuge for them. Disturbance by visits, setting up fireplaces near caves, negatively affect their survival in this difficult period. In case of early or repeated awakening, they can die due to the consumption of energy, which is necessary to start metabolism, increase body temperature after hibernation, and for the period of early spring with fickle weather and irregular availability of food. Bats can also become infected with viral diseases transmitted by us during wintering. Therefore, let’s be considerate and save visits to caves for the period outside of winter.
Individuals of some species of bats can live for more than 30 years. All bats and amphibians occurring in Slovakia are protected by law. They perform an important regulatory function in the ecosystem – one bat can hunt several hundred insects during one night during the summer and they themselves become prey for their predators.
Text: Ing. Apfelová, Mgr. Pekárová
Photo: archive of S-NPVF
