1. Center for Ecology and Environmental Research; Vilnius University; Vilnius 03101 Lithuania
2. Institute of Life Sciences and Technology; Daugavpils University; Daugavpils 5401 Latvia
3. School of Geography and the Environment; University of Oxford; Oxford OX1 3QY UK
4. Center for Macroecology, Evolution and Climate, National Museum of Natural History; 2100 Copenhagen Denmark