The decline of black grouse
 

The last estimate of black grouse numbers in Britain was 6,500 displaying males in 1996, with the population centred on a few key upland areas of Scotland, northern England and Wales. 150 years ago black grouse were more numerous and widespread and they could be found on many heaths of southern and eastern England.The decline and contraction of range seems to have begun about a century ago following gradual improvements in farming.

Most worrying is that in the late 1990s the black grouse was declining at a rate of some 8-10% per year with a geographical range that was continuing to contract.

Black grouse bags 1900-2000

Trend in the numbers of black grouse shot from British estates during the 20th century. Data from The Game Conservancy Trust’s National Gamebag Census key data set of 84 estates that have 80% complete records since 1900. Some 30+ of these places were shooting black grouse between the wars.
 

Today’s continuing loss seems to stem from the following:

  • Loss of habitat mosaic. Land-use used to be mixed. Black grouse favour a patchwork quilt of farmland adjacent to moor and forest, and they need a sweep of suitable countryside to sustain their population. Contiguous areas have been broken up by block forestry and intensive farming.
  • Over-grazing. High densities of sheep and red deer eat out ground cover, thereby reducing the abundance of caterpillars that grouse chicks need.
  • Changes in forestry. Black grouse like the ground cover in young plantations, but as these develop into solid conifer thickets they tend to leave. Forest edge used to melt into heathland through a transition of scattered trees; today’s forests are hard edged.
  • Increased mortality. Because they are now more common, crows foxes, stoats and some birds of prey cause a high annual loss. In addition, forest deer fences kill many birds.
Suitable habitat (based on the analysis of the Centre of Ecology and Hydrology land cover map) is shown as either blue, where black grouse are currently present, or green, where they are absent. Based on The New Atlas of Breeding Birds in Britain and Ireland:1988-1991and recent information.
A male black cock displaying on a lek. (Laurie Campbell)
    A bird of the upland fringe
Contents
The black grouse recovery plan