1. Department of Plant Ecology and Physiology, Institute for Water and Wetland Research Radboud University Nijmegen The Netherlands
2. Smithsonian Tropical Research Institute, Apartado Postal 0843‐03092 Balboa Ancón Panamá
3. Department of Ecology and Evolutionary Biology Princeton University Princeton New Jersey USA
4. Department of Animal Ecology and Physiology, Institute for Water and Wetland Research Radboud University Nijmegen The Netherlands