1. Institute of Biological Sciences, University of Stirling, Stirling FK9 4LA, UK
2. Department of Computing Science and Mathematics, University of Stirling, Stirling FK9 4LA, UK
3. Rabbitwise Consultancy, Holtside, Batts Corner, Dockenfield, Farnham, Surrey GU10 4EX, UK
4. NERC Centre for Ecology and Hydrology, Oxford, Mansfield Road, Oxford OX1 3SR, UK