It is important to note that habitats can appear to have a different species composition to the standard habitat definitions. This could be the result of changes due to human activity and land management.[Description]
'The same stretch of Glen Esk moorland before (top, 1960, with cock grouse on its territory and a pile of limestone ready for spreading), and after conversion (botton, 1994, heather has been 'improved' to grass, through government subsidy).'
Watson, A; Moss, R (2008). Grouse. London: HarperCollins. 390.