1 Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, SE-907 36 Umeå, Sweden. Electronic address: michael.bertram@slu.se.
2 Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX 78712, USA.
3 Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK.
4 Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, SE-907 36 Umeå, Sweden.