Does rotational heather burning increase red grouse abundance and breeding success on moors in northern England?

Abstract

Rotational burning of moorland vegetation is considered by grouse moor managers to create structurally diverse habitat that helps maximise red grouse Lagopus lagopus scotica (Lath.) abundance for shooting by increasing breeding success and adult survival. However, there is growing concern that increasing levels of burning, particularly on deep peat, are impacting upon upland ecosystems. We used linear mixed models to examine the influence of burning on heather Calluna vulgaris (L.) height and structure, and on grouse density and breeding success, at 36 moors in northern England which practiced driven grouse shooting and employed full-time gamekeepers to burn heather, but also to control generalist predators of grouse and their parasitic nematode worms. Variation in heather height was positively associated with burning extent on moors and the relationship between heather height and burning was similar on moors of deep (blanket bog) and shallow peat (heath). Grouse pre-breeding density was not related to burning extent, but breeding success and post-breeding density were positively associated with extent of burning on moors. Relationships between grouse and burning were similar on heath and blanket bog. Higher grouse breeding success and post-breeding density were likely to be associated with a more varied vegetation structure following burning. Rotational burning is associated with higher grouse breeding success and post-breeding densities beneficial for driven grouse shooting. Thus a conflict may exist between rotational burning to benefit grouse and potential impacts of burning on ecosystem services such as carbon storage and flood protection. Potential benefits of burning for increasing grouse breeding success and post-breeding density need to be considered carefully against any likely impacts on ecosystem services, particularly in areas of blanket peat.