[1
]Biological and Environmental SciencesFaculty of Natural SciencesUniversity of Stirling
Stirling UK
[2
]School of Biological SciencesUniversity of Aberdeen Aberdeen UK
[3
]Department of EcologySwedish University of Agricultural ScienceGrimso Wildlife Research
Station Riddarhyttan Sweden
[4
]School of GeoSciencesUniversity of Edinburgh Edinburgh UK
[5
]Scottish Natural Heritage Edinburgh UK
[6
]NERC Centre for Ecology and Hydrology Penicuik UK