Winter, the time of rest for bats, is an intense time of field work for chiropterologists who have to count the animals in their winter roosts. In January and February the project team and volunteers visited 87 bat hibernacula in the Lower Silesian, Lesser Poland, Opole and Subcarpathian voivodeships. Out of about 1800 bats encountered, 771 were lesser horseshoes. Also numerous were Daubenton’s and greater mouse-eared bats.

The winter bat census is not just a method of estimating bat populations, it is also an occasion to assess the condition of the roosts and identify the threats for the bats and/or their habitat. The most urgent work was planned. Six of the visited roosts require immediate protection against amateur underground tourism and/or collapse. In two caves located in the south-eastern part of the country protective grills were damaged and need repair. In two other roosts work is needed to improve the microclimate inside.