
History and population trendsHow many in Britain?The black grouse has undergone a serious decline in population and range in Britain over the last century. Highly prized by sportsmen, 'game bags' provide an insight into their dramatic decline and show that they have been lost from many areas where they were once abundant. The population has been estimated several times, but each by a different method, so the estimates are not directly comparable. In 1973, a very rough estimate put it at between 10,000 and 100,000 males (Parslow), though it is believed that the true figure was well within the lower half of this range. In 1988-91, the BTO New Atlas of Breeding Birds estimated that there were 10-15,000 females and 13,000-19,500 males, given a ratio of 1.3 cocks per hen. In the early 1990s, Baines & Hudson used a combination of bird surveys and landowner questionnaires to estimate that there were 25,271 (95% cl 13,800 - 36,700) lekking males. However, during the 1990s the average rate of decline across Britain was believed to be 10% per year. It was not until the first systematic survey was carried out in 1995/96 (by The Game Conservancy Trust, RSPB and Scottish Natural Heritage), that a robust estimate of the population was possible. This survey (Hancock et al. 1999) estimated there to be 6,500 lekking males. In 2005 this figure had decreased to 5,100 lekking males. While numbers were stable and increasing in Wales and northern England, populations in some areas of Scotland had suffered severe declines. Efforts to find out how this trend can be reversed are underway. Trends In western Scotland, the remaining black grouse are found predominantly around forestry plantations, while in southern, eastern and parts of northern Scotland, they are most associated with the edge of moors managed for red grouse shooting. Wales England There were several attempts in the 19th century to introduce or reintroduce black grouse, including in Buckinghamshire, Orkney and even Ireland, where there are no previous records of black grouse. None of these attempts were successful in the long term. In Northern England, black grouse are showing encouraging signs of recovery
with national surveys of lekking males in 1998, 2002 and 2006 showing
increases in both numbers and range from 773 males, occupying 74, 5 km
grid squares in 1998, to 1,029 males, occupying 93, 5 km grid squares
in 2006. The core of the English population, found in the North Pennines,
is stable, with exceptional increases on the southern edge of their range
in the Yorkshire Dales, of 138% between 1998 and 2006.
Year of extinction in a selection of English counties and areas. |