1 Field Station Fabrikschleichach, Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, 96181 Rauhenebrach, Germany. simon@thornonline.de.
2 Field Station Fabrikschleichach, Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, 96181 Rauhenebrach, Germany.
3 Bavarian Forest National Park, 94481 Grafenau, Germany.
4 Department of Ecology, University of Granada, 18071 Granada, Spain.