From `Birds', the magazine of the RSPB, Spring 1998. Hen Harriers - a legitimate grouse? ----------------------------------- On 31 October 1997, after months of speculation and rumour, the results of the Joint Raptor Study were published. This five-year research project brings into sharp focus the need for conservationists, grouse moor owners and managers to work together to secure a better future for moors that are rich in wildlife, good for game management and good for local communities. The Study investigated the effects of raptor predation on the numbers of red grouse: hen harrier and peregrine were the subjects of the research. In the light of some of the speculative media comments on the Study, both before publication and afterwards, it is very important to remember that it is essentially about hen harriers, peregrines and red grouse and not the moorland bird community as a whole. Some raptors, including hen harriers and peregrines, eat a lot of grouse. They eat many other things too but it is their predation on grouse which has always made them unpopular on grouse moors. The reports we publish every year on offences against wildlife legislation show that raptor killing is widespread, with a large proportion of offences associated with grouse-shooting areas. This winter, the Scottish Raptor Study Groups, in a paper in Scottish Birds, showed how hen harriers, golden eagles and peregrines are routinely persecuted on managed grouse moors. Most damning of all, our published research on hen harriers in Scotland has shown that deliberate killing of adults and nest destruction is routine on managed moors, so much so that it has held the harrier population in check for years. Against such a troubled background, it made sense to examine the role of raptors on grouse-moors more closely, particularly as the clamour for licensed control of birds of prey became louder. The RSPB willingly played a major role in the Joint Raptor Study, helping to fund and direct it. The work was undertaken by Dr.. Steve Redpath of the Institute of Terrestrial Ecology and Dr. Simon Thirgood of the Game Conservancy Trust. They looked at six Scottish grouse-moors, on all of which there was agreement that there would be absolutely no illegal killing of birds of prey. Driven grouse shooting (the system established by long tradition where beaters drive the birds towards static 'guns') existed on only two of these: Langholm, on the Buccleuch Estate in southern Scotland (very much the centre of the project), and an area known only (at its owner's request) as 'Moor C'. The Study showed that, where left alone, birds of prey will increase from the low densities imposed by human persecution. This effect was very marked at Langholm, where hen harriers increased from just two pairs in l992 to 14 breeding females in 1996 and peregrines from three pairs in 1992 to six in 1994 and 1995 and five in 1996. Elsewhere, increases were less dramatic: on `Moor C' hen harriers, after numbering six breeding females in 1991, declined gradually to only two in 1996, while peregrine numbers remained roughly stable at two or three pairs. Reduced bags: not populations ----------------------------- It was also shown that peregrines and hen harriers eat grouse throughout the year. At Langholm, in the years with highest raptor numbers, losses of adult grouse in spring and chicks in summer were high, but, despite all this, spring numbers (the breeding population) remained constant throughout the study. Birds of prey were not wiping out the grouse population - but they were affecting the autumn 'bag': overall, it decreased by up to half during 1992-96, and by over 90% in the last two years of the study. In essence, raptors were eating the grouse a few weeks before the 'guns' could shoot them. For the time being at least, driven grouse shooting is no longer viable at Langholm. This effect, in contrast, was not seen on 'Moor C', where bird of prey numbers remained at a level which left driven shooting viable: over 2,000 grouse were shot on this moor in 1996. Red grouse bags have fallen at Langholm by about 1.7% per year for more than 80 years. For about half that time, birds of prey were unprotected in the UK and effectively 'controlled'; for most of it hen harriers would have been absent or very scarce. Only recently have bird of prey numbers begun to recover. The study considers it highly improbable that birds of prey are responsible for the long-term fall in grouse bags and cites habitat change as much the most likely explanation. Sheep: the real enemy --------------------- Between 1948 and 1988, almost half the heather-dominated vegetation so crucial to red grouse gave way to grass at Langholm, with particularly heavy losses of heather on the lower ground. This was the result of heavy grazing by sheep. The remaining mixture of grass and heather is ideal for high densities of meadow pipits and voles - the main prey of hen harriers and probably the key to the rapid increase of harriers at Langholm. On 'Moor C', at a higher altitude where heather has maintained it's dominance, pipit and vole numbers are much lower and, consequently, so are those of hen harriers. One thing the Joint Raptor Study has shown is that birds of prey eat many grouse; another, very clearly, is that where they are left alone birds of prey will increase. Other important messages are clear enough. A heather-grass mix, the result of overgrazing, is not only poorer grouse habitat than well - managed heather but, because it is likely to hold high densities of voles and pipits, it is very attractive to harriers, which in high numbers could (as at Langholm) seriously depress grouse bags. The greatest enemy of red grouse is the sheep - not the harrier or peregrine. Raptors are not driving grouse populations into extinction, nor are they responsible for long-term declines in grouse bags. Langholm lies at one end of the spectrum, but it could be replicated on other overgrazed moors if bird of prey persecution ceased. In contrast, on heather dominated 'Moor C' hen harriers can co-exist with driven grouse shooting. Future action ------------- What comes next? Obviously, the starting point is the best possible management of the remaining heather-dominated moors, not technically a problem since appropriate methods are well understood but financially more difficult. It is very clear that, in the long term, the future of heather moorland as a valuable wildlife habitat - good for birds of prey and grouse alike, as well as many other species - lies also in \plain\f4\fs18 halting the loss of heather to overgrazing and inappropriate forestry. \par \pard\li270\plain\f4\fs18 Nobody pretends that this is going to be easy. This is because the main problems have to do with money and complexities of land use policy. Without better financial incentives for moorland management, including shepherding and keepering, and a change in the system of subsidies so that sporting use competes on a level playing field with livestock farming and forestry, the future for some grouse moors and the birds and people who depend on them may be bleak, with or without raptors. The spirit of co-operation throughout the Joint Raptor Study, very apparant on the day its results were made public, encourages us to believe that landowners, shooting interests and statutory and voluntary wildlife conservation bodies work together: the RSPB is committed to keeping the spirit alive and calls on all interests to act together to achieve effective financial subsidy for upland management, for conservation, shooting and the rural employment associated with each. Killing birds of prey is no answer to grouse moor problems, not even in the extreme situation which has arisen at Langholm: encouragingly, the Earl of Dalkeith, who owns Langholm, stated publicly at the launch of the report that raptor killing was completely unnacceptable. The Scottish Landowners' Federation, which had called for licensed killing of raptors, has abandoned this stance. This is a positive move. All organisations seem committed to finding practical, acceptable solutions to the problems of upland management. The RSPB will participate fully and constructively in these discussions. There is much to be gained in the uplands, as in the lowlands, from more sensitive land management which could create a better future for upland birds and upland people alike. In the short term, we must look for solutions for Langholm. A controversial proposal to move harriers to other moors is mooted but remains to be considered in detail: we doubt its feasibility and effectiveness. A more promising solution, perhaps, might be to provide substitute food for harriers to take pressure off red grouse at the most crucial times. This, too, requires full discussion. The RSPB seeks an end to persecution of birds of prey and, equally, wants a `new deal' for the uplands, with land-use policies helping wildlife, game management, the rural economy and people.