Europe’s mountain regions, above and north of the natural treeline, have some of the world’s most natural habitats. This is the arctic-alpine zone, and being treeless and not having experienced widespread managed fires, tree felling and associated human-related disturbance, is more ‘natural’ than the subalpine and lower ‘upland’ zones (Chapter 8). However, many arctic-alpine areas are grazed by livestock, with some experiencing acidic deposition and a range of pollutants and recreational influences, and so are ‘near-natural’ rather than ‘natural’ in the strictest sense. A small number of bird species are confined to the arctic-alpine zone – the alpine specialists (Ratcliffe and Thompson, 1988; Ratcliffe, 1990, 2005; Thompson et al., 1988, 2003; Calladine, 2011). Many more generalists (which also nest at lower elevations, in a variably broader range of habitats) also breed in these areas. This chapter provides an overview of the breeding birds and their habitat use in the arctic-alpine zone of British and Scandinavian mountains. It considers conservation and management issues, as well as some broad differences between the two regions, focusing on specialists and generalists. We do not consider the wider range of species which only feed, rather than nest, in the arctic-alpine zone because most of these spend only a small amount of time foraging there (Ratcliffe, 1990; Calladine, 2011). Unlike Scandinavia, Britain has virtually no natural treeline habitat, and accordingly has a much lower structural diversity of habitats in its arctic-alpine zone (e.g. Ratcliffe, 1977, 1990, 2005; Ratcliffe and Thompson, 1988; Ashmole, 2011).
Arctic-alpine areas are influenced by changing climate, land-use practices and other factors such as pollution (Pearce and van der Wal, 2002; Thompson et al., 2005; Welch et al., 2005; Shaw and Thompson, 2007; Thompson and Whitfield, 2007; Armitage, 2010; Albon, 2011; Austrheim et al., 2011; Pearce-Higgins, 2011a, b). It is important that we understand the nature of relationships between bird distribution and habitats in these extreme environments, where even small changes in climate or some other key variables may influence significant habitat or species responses. As many of the nesting species cannot move higher or further north, they face local or even regional losses if habitat changes are extreme.