1. Wildlife Ecology and Wildlife Management; University of Freiburg; Tennenbacherstraße 4 79106 Freiburg Germany
2. Forest Research Institute of Baden-Württemberg FVA; Wonnhaldestraße 4 79100 Freiburg Germany
3. Department of Biometry & Environmental System Analysis; University of Freiburg; Tennenbacherstraße 4 79106 Freiburg Germany
4. School of Biology and Environmental Science; University College Dublin; Belfield Dublin 4, Ireland