The densely crowded, upside down hibernate and drawing from the summer fat reserves is over. The first bats are already slowly leaving their caves and searching for insects. Since April 6th, 2019, the 'Waldbox' (forest box) incl. Batcorder (ultrasound detector) is ready to record the sounds of the bats. Karin Widerin from the Coordination Center for Bat Protection and Research in Austria…