The role of habitat change in driving Black Grouse Tetrao tetrix population declines across Scotland.

CapsuleBlack Grouse declines across Scotland were greatest on less heterogeneous moorland, at low to intermediate altitudes and, more weakly, around post-thicket woodland. AimsTo examine correlates of change in abundance of Black Grouse across Scotland. MethodsChanges in abundance within 5-km squares between national surveys in 1995/96 and 2005 were modelled in relation to measures of habitat cover and woodland age derived from satellite imagery. ResultsPopulations across Scotland were most stable where unenclosed moorland comprised rough grassland, intermediate heather cover and at higher altitude. Declines tended to be greatest in squares which had transitioned from pre-thicket to closed-canopy woodland. ConclusionMoorland will be most beneficial where it is heterogeneous in composition, and the role of woodland maturation in driving regional declines has support, albeit more weakly, at a national scale. [ABSTRACT FROM PUBLISHER]