Resolving the conflict between driven-grouse shooting and conservation of hen harriers
*Correspondence author. E-mail: pat.Thompson@rspb.org.uk
1. Birds of prey and driven-grouse shooting are at the centre of a long-standing human–wildlife conflict. Hen harrier predation can reduce grouse shooting bags, limit grouse populations and cause economic losses. Despite legal protection, hen harrier numbers are severely depleted on driven-grouse moors.
2. In limited trials, provision of supplementary food to hen harriers greatly reduced their predatory impact on young grouse, but did not result in higher grouse densities for shooting. Consequently, grouse moor managers have failed to adopt the technique.
3. A recent Forum paper has called for a trial ‘population ceiling scheme’ for hen harriers, arguing that this represents the best way to increase hen harrier numbers on driven-grouse moors. Once densities exceed the agreed ceiling, the excess would be translocated to other suitable habitat.
4. Whilst a ‘ceiling’ scheme might work, it would be difficult to implement and we believe that other approaches to population recovery should be tested first.
5. While driven-grouse shooting makes an important economic contribution to some rural communities, some grouse moor owners receive considerable sums of public money. Despite this, many moors are in poor condition, the ecosystem services they supply may be at risk from both climate change and current management practices, and grouse numbers are in decline. The socio-economic and environmental implications of alternative models of grouse management need urgent examination.
6. Synthesis and applications. If driven-grouse shooting is only viable when birds of prey are routinely disturbed and killed, then we question the legitimacy of driven-grouse shooting as a sustainable land use. Moorland owners need to consider more broadly sustainable shooting practices for the 21st century.
In a recent Forum article, Thirgood & Redpath (2008) (T&R) explore barriers to resolving a long-standing conflict between hen harrier Circus cyaneus (L.) conservation and management of red grouse Lagopus lagopus scoticus (Latham) for sport shooting in the UK. They find little evidence of progress towards resolution since research which showed that when hen harrier populations were protected from illegal disturbance and killing, their population increased, and their predation of red grouse chicks was sufficient to reduce shooting bags, limit grouse populations and ultimately cause the estate to become economically unsustainable as a driven grouse moor (Redpath & Thirgood 1997).
These findings came from just one site, Langholm Moor, but have been widely extrapolated by grouse moor managers to their own circumstances. Illegal disturbance and killing have continued, are implicated in declines of hen harriers in grouse moor areas (Etheridge, Summers & Green 1997; Sim et al. 2007) and extend to other raptors, including golden eagle Aquila chrysaetos (L.) and peregrine falcon Falco peregrinus (Tunst.), with similar effects on range and population size (Hardey, Rollie & Stirling-Aird 2003; Whitfield et al. 2004). All this has happened against a background of strengthened wildlife protection legislation reflecting society’s condemnation of wildlife crime.
Thirgood & Redpath (2008) conclude that entrenched positions of stakeholders obstruct progress, and they propose two solutions based on managing hen harrier populations. We suggest that a balanced debate should also consider whether more flexible grouse moor management might accommodate unmanaged hen harrier populations. Our objective is to broaden the conventional framing of this conflict. Reaching a sustainable, long-term solution should be considered in the context of broader, more challenging environmental, social and economic questions facing the future management of the UK’s uplands (Orr et al. 2008).
Proposed solutions based on management of hen harriers
Thirgood & Redpath (2008) consider two solutions: (i) diversionary feeding of hen harriers, and (ii) setting ‘ceiling’ hen harrier densities on grouse moors.
This technique involves providing carrion to nesting hen harriers. Trials have shown that it could reduce provisioning rates of grouse chicks to hen harrier nests sevenfold (Redpath, Thirgood & Leckie 2001), but this did not translate into an increased shootable surplus. We agree with T&R that the latter finding has overshadowed the success of the technique in reducing the predatory impact of harriers, and fostered reluctance amongst grouse moor managers to adopt it, despite Government funding. We agree with T&R and the UK Raptor Working Group (2000) that the efficacy of diversionary feeding should be tested more widely. At present, only the Langholm Moor Demonstration Project (2009) is further testing diversionary feeding (at the original trial site; Appendix S1), but this is not an experimental study. Further studies should test experimentally whether the provision of diversionary food increases harrier settling densities, potentially negating the benefits of reduced predation of grouse by individual harriers.
Setting ‘ceiling’ densities for hen harriers on grouse moors
Thirgood & Redpath (2008) proposed a trial to assess the feasibility of implementing ‘ceiling’ densities of hen harriers on grouse moors, with additional birds translocated to other habitats. Legally, hen harrier conservation must be the objective because no provision exists for derogation from EC Directive 79/409/EEC on the Conservation of Wild Birds (the Birds Directive) to deliver a grouse surplus for sport shooting. The trial would test whether this approach could allow hen harrier populations to increase on grouse moors whilst minimizing harrier predation impacts on grouse bags. However, the necessary derogation from the Birds Directive could only be considered if stakeholders supported the trial. This presents difficulties, both in principle and in practice. As a point of principle, it seems inappropriate to us to set a maximum density for a species of high conservation concern included on Annex 1 to the Birds Directive, and subject to special conservation measures. Population targets are used more appropriately to set minimum achievable goals for conservation programmes. From a more pragmatic perspective, we have two concerns. First, a ‘ceiling scheme’ for hen harriers would precipitate calls to limit populations of other raptor species (e.g. buzzard Buteo buteo L. and red kite Milvus milvus L.), for which there is no evidence of economic impact. Secondly, this approach cannot offer a long-term solution because, as Watson & Thirgood (2001) point out, it would need to continue in perpetuity despite the fact that there will be only a limited availability of suitable recipient sites for translocated birds.
These challenges to the feasibility of a ceiling scheme are formidable and suggest to us that the ‘cascade approach’ (T&R) to conflict mitigation where less intrusive techniques are first tested conclusively (UK Raptor Working Group 2000) remains robust. A ‘ceiling’ scheme should be regarded as a last resort, as it is in law.
In focussing on diversionary feeding and a ‘ceiling’ scheme, T&R rule out other options. One alternative under current discussion (The Environment Council 2009) may have some merit. Under this proposal, developed by Steve Redpath (from hence called the brood management scheme), harrier settling densities would not be limited, but if numbers of successful nests (at hatching) were above a threshold level compatible with driven-grouse shooting (Redpath & Thirgood 2003), the broods of nests above this threshold would be collected, hand-reared and released locally after fledging. These methods have been developed and applied successfully to reduce losses suffered by crop-nesting harriers in France (Arroyo, Garcia & Bretagnolle 2002) and Spain (B.E. Arroyo, personal communication), and much practical experience has been gained that could be applied in any UK interventions. For stakeholders to have confidence in a trial scheme of this kind, illegal killing of hen harriers and other raptors must stop. Indeed, this is a key success criterion for any trial. It is difficult otherwise to see how confidence can be built in the current climate of ‘zero tolerance’ of hen harriers on many grouse moors, and calls from some interests to limit the populations of other raptor species.
Other options involve no direct management of hen harriers. The recovery of golden eagle populations might limit hen harrier densities in grouse moor areas (Fielding et al. 2003). T&R’s observation that current illegal killing of golden eagles would make it difficult to test this idea seems a compelling reason to explore it further. The outcome could be a ‘win–win’ solution for raptor conservation and grouse management, could reduce illegal killing of two species of raptor, and would be consistent with governing legislation. Pending the necessary research, this and other approaches, including long-term restoration of heather cover (Thirgood et al. 2000a) should remain in the conflict–resolution toolbox.
Economic and environmental costs and benefits of grouse management
Thirgood & Redpath (2008) note that grouse management provides ecological, social and economic benefits. Sport shooting contributes to the UK’s rural economy (Anon 2006), but its importance has not been well quantified, and the contribution of grouse shooting to the Gross Domestic Product (GDP) is small especially in the context of the land area managed (Appendix S2). It is generally agreed that over the 7–12 years of the grouse population cycle, few landowners generate a net profit solely from grouse shooting revenues (e.g. Fraser of Allander Institute 2001; Watson & Moss 2008). Grouse management has helped to slow rates of loss of heather moorland (Robertson, Park & Barton 2001), a habitat type for which the UK has global conservation responsibility in part because of the bird assemblages supported (Thompson et al. 1995), and is associated with higher densities of some upland breeding birds (Tharme et al. 2001). However, there is no evidence that driven-grouse shooting is critical to the delivery of economic or environmental benefits in the uplands. Yet this uniquely British form of grouse shooting (Appendix S3), where lines of beaters flush grouse over static guns, requires the maintenance of post-breeding densities >60 birds km2 of red grouse, and creates conflict with raptor conservation (Hudson 1992). Driven shoots have been the core objective of grouse moor managers since the mid-1800s, but evidence of the environmental impact of inappropriate heather burning on habitat condition (especially blanket bog), deep peat soils and water colour is growing (Stewart, Coles & Pullin 2004; Yallop et al. 2006; Natural England 2008). This intensive, landscape-scale approach to shoot management differs markedly from hunting-styles prevalent across most of Europe (Viñuela & Arroyo 2002). Market and economic research, to determine the consequences of alternative, lower input, lower output models of grouse shooting is now required.
Long-term challenges and the need for a broader perspective on upland futures
Thirgood & Redpath (2008) note that one entrenched position in the hen harrier–red grouse conflict is that grouse shooting is a traditional sport with management techniques that are slow to change. Today, two dominant land uses in Britain – agriculture and forestry – have made huge strides in achieving a more sustainable balance between their primary roles in the production of food and fibre and the delivery of public goods and services, including wildlife conservation (Marren 2002). In this context, the maintenance of a leisure interest in competitive killing of birds cannot justify the widespread limitation of densities of legally protected birds of prey in the 21st century (Ratcliffe 2007), especially when many moor owners and tenants receive substantial public subsidy under the Common Agricultural Policy.
That large tracts of heather moor in the UK should continue to be managed for driven-grouse shooting under the current business model can therefore be questioned, and alternatives should be explored. Is it possible, for example, to manage moors less intensively, producing fewer grouse, but increasing the net margin on hunting income? Examples of such ‘walked-up’ grouse shoots already exist in Scotland and could offer valuable insights. Other public benefits may result through better safeguarding carbon-rich peat soils, water yield (and quality) and a more diverse upland system in comparison with intensive, driven-grouse management (Yallop et al. 2006; Orr et al. 2008; Watson & Moss 2008). At the very least, research is needed to test whether alternative models for grouse moor management could deliver a more sustainable combination of economic, social and environmental benefits.
Broader approaches to management of upland systems can certainly bring tangible economic benefits. For example, in 1977 the Abernethy estate in Speyside, Scotland, supported 1·5 full-time equivalent (FTE) jobs (a gamekeeper and a part-time gillie). Today, under conservation management, it employs over 20 FTE jobs (Walton & Housden 2007). Birds of prey can also be income sources for moorland owners and local communities. Public viewing schemes attract hundreds of thousands of visitors each year. White-tailed eagles Haliaeetus albicilla (L.) alone contribute £1·4–1·6 million per year to the local economy of the Scottish island of Mull and support 30–40 FTE jobs, and visitors to osprey Pandion haliaetus (L.) viewing sites around the UK spend an estimated £3·5 million per year (Dickie, Hughes & Esteban 2006).
Climate change may also challenge maintenance of red grouse at population densities necessary to sustain driven-shooting. Climate envelope predictions that UK distribution of conditions suitable for red grouse may contract markedly to the north during this century (Huntley et al. 2007) should be interpreted cautiously, but suggest that intensive grouse management may become more difficult. Hudson, Newborn & Dobson (1992) and Hudson et al. (2006) predict that climate disruption may lead to increased frequency and intensity of disease outbreaks caused by the nematode parasite Trichostrongylus tenuis (Mehlis in Creplin), which may induce grouse population crashes. Similarly, Kirby et al. (2004) found a fivefold increase in sheep tick Ixodes ricinus (L.) (the vector of the grouse viral disease, louping ill) burdens on red grouse chicks, and an increase in the percentage of chicks carrying ticks from 4% to 92% between 1985 and 2003, partly because of climatic changes.
The way forward
Thirgood & Redpath (2008) conclude that hen harriers continue to be the losers in this conflict. We agree, but throughout much of Great Britain, red grouse have also been declining for decades (Hudson 1992; Thirgood et al. 2000b) driven mainly by habitat change, and despite widespread declines of hen harrier, golden eagle and peregrine in grouse moor areas. For example, during the period 1998–2004, the only hen harrier populations to decline were in the uplands of southern and eastern Scotland and northern England, the key grouse moor areas (Sim et al. 2007), yet long-term declines in grouse bags continue (Davey & Aebischer 2008).
It is difficult to accept that hen harriers should be maintained at levels well below those they would otherwise attain within core parts of their breeding range given that the causes of grouse population decline lie elsewhere, and other causes of grouse bag reduction are numerous (Thirgood et al. 2000b). From the perspective of hen harrier conservation, most of this species’ habitat in Britain was lost long ago to enclosure and agricultural conversion of heaths, downs and wetlands that were once widespread (Shrubb 2003). Hen harriers have become restricted to upland heath by intensive management of the lowlands. We argue that the last thing we should do is to accept limited hen harrier densities in these remaining habitats. Rather we should seek to meet ambitious population targets, just as have been achieved for other species whose ranges have become severely restricted by intensification of land management [e.g. corncrake Crex crex (L.) and stone-curlew Burhinus oedicnemus (L) (Wilson, Evans & Grice 2009)].
To move beyond the current stalemate, rapid progress is required in five respects. First, hen harriers and other birds of prey must be allowed to settle and breed successfully on grouse moors, in a context of firmer law enforcement that focuses on known problem areas and implementation of more effective crime prevention and detection strategies. The recent Thematic Review of Wildlife Crime in Scotland (Scottish Government 2008) endorses this view. The development and promotion of a quality standard mark for grouse moors, awarded in recognition of environmentally friendly management might help establish models of best practice. Where such an approach fails, Governments could regulate the shooting sector more effectively by introducing a compulsory licensing scheme for individual shoots. This would ensure adherence to a set of commonly agreed standards, including compliance with legislation. Failure to adhere could result in a shoot’s licence being withdrawn by the courts – a much tougher penalty than is currently available, and a stronger deterrent to those prepared to break the law, or tolerate such action by their employees. Secondly, diversionary feeding should be tested widely. Thirdly, research is needed to assess whether recovery of golden eagle populations could assist in limiting predatory impacts of hen harriers on grouse populations. Fourthly, there may be merit in exploring whether a trial brood management scheme could assist in reducing harrier predation on grouse with the objective of achieving a rapid improvement in harrier conservation status on grouse moors. Finally, interdisciplinary research should explore how the private interest of grouse shooting can work more closely and flexibly with the future delivery of public goods given wider public expectations as to how our uplands are to be managed. This includes delivery of ecosystem services such as carbon and water resources (Orr et al. 2008), public access, and protection of natural heritage (Defra 2007; Ratcliffe 2007), as well as contributions to rural economies.
It is incumbent on grouse moor owners to demonstrate that their stewardship of large tracts of the UK’s uplands is founded on sustainable principles capable of delivering multiple benefits. Given the levels of public funding directed to managing the uplands, many areas of which are of European significance for their biodiversity, the public and a range of other stakeholders have a right to be involved in deciding how they are managed in the future. Managing the land for shooting will continue to be important, but only if the grouse-shooting sector is prepared to co-exist with birds of prey. Any serious attempt to resolve the grouse–harrier conflict needs to take into account the wider context of environmental delivery and public opinion, and seek solutions across the range of management options available – including alternative models of grouse shooting.
The authors are grateful to Andy Brown, Sue Armstrong-Brown, Mark Avery, Ian Francis, Stuart Housden, Julian Hughes, Peter Mayhew, Duncan Orr-Ewing, Paul Walton, Beatrice Arroyo and two referees for improving the text, and Ian Dawson and Lynn Giddings for sourcing key reference materials.