1. Department of Ecology-Animal Ecology; Faculty of Biology; Philipps-Universität Marburg; Karl-von-Frisch Straße 8 35032 Marburg Germany
2. Terrestrial Ecology Research Group; Department of Ecology and Ecosystem Management; TUM School of Life Sciences Weihenstephan; Technische Universität München; Hans-Carl-von-Carlowitzplatz 2 85350 Freising-Weihenstephan Germany
3. Swiss Federal Research Institute WSL; Zürcherstrasse 111 8903 Birmensdorf Switzerland