British moorlands are a semi-natural habitat, created and maintained for millennia by land management activities through grazing, burning and peatcutting to produce a mosaic of plant communities of varying composition and structure (Backshall et al., 2001). This mosaic is associated with a diverse suite of animal species (Usher and Thompson, 1993; Thompson et al., 1995) – particularly birds (Pearce-Higgins et al., this volume) – and is valued as a resource for livestock, game, recreation and tourism (Condliffe; Curry; Sotherton et al., all this volume).