1. Centre for Ecological and Evolutionary Synthesis (CEES), Dept of Biosciences, Univ. of Oslo; PO Box 1066 Blindern NO-0316 Oslo Norway
2. Dept of Ecology and Natural Resource Management; Norwegian Univ. of Life Science; PO Box 5003, NO-1432 Aas Norway
3. Museum of Natural History and Archaeology, Section of Natural History, Norwegian Univ. of Science and Technology; NO-7491 Trondheim Norway