Landscape fragmentation and the decreasing number of natural habitats have brought bat populations to their historical minimum. In this research bats´ preferences for maternity roost buildings were studied. Within 17 fieldwork nights during midsummer 21 roost sites in Western Saaremaa were mapped and later analyzed with QGIS in different size buffers while comparing the results to randomly selected buildings. Landscape analyses showed that colonies of northern bat were positively correlated to length of surrounding woodland edge and negatively to amount of human related land-classes. The simplest measures for changing the landscapes while also considering the well-being of northern bat would be observing the ratio of open and wooded land classes and regulating the density of buildings.


Karl Hendrik Tamkivi