Environmental Impacts of High-Output Driven Shooting of Red Grouse
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Ibis (2016), 158, 446–452 Viewpoint ulating quarry species, hunting season and permitted hunting methods. There is no statutory requirement for hunters to report their bags, although records are col- lected by a non-profit organization, the Game & Wildlife Environmental impacts of Conservation Trust (GWCT). This combination of inten- sive shooting practice with weak regulation is almost high-output driven unique (Mustin et al. 2012), and offers general insights shooting of Red Grouse into the environmental impacts of intensive game man- agement when managers operate without much of the Lagopus lagopus scotica regulation recommended by Loveridge et al. (2009). PATRICK S. THOMPSON,1* DAVID J. T. DOUGLAS,2 There is growing public debate about these impacts DAVID G. HOCCOM,3 JEFF KNOTT,3 (Thompson et al. 2009, Avery 2015, Wightman & Tin- STAFFAN ROOS2 & JEREMY D. WILSON2 gay 2015), part of a wider trend of public engagement in 1RSPB, 1 Sirius House, Amethyst Road, hunting policy (Minnis 1998). For example, the recent Newcastle-upon-Tyne NE4 7YL, UK near-extirpation of the Hen Harrier Circus cyaneus as a 2RSPB Centre for Conservation Science, RSPB breeding bird in England (Redpath et al. 2010) and Scotland, 2 Lochside View, Edinburgh Park, claims of mass culls of Mountain Hares Lepus timidus in Edinburgh EH12 9DH, UK Scotland by grouse moor managers (Anon 2014) has 3RSPB, The Lodge, Sandy, Bedfordshire SG19 2DL, UK prompted three UK public petitions to license or ban dri- ven grouse shooting, one for the introduction of vicarious liability (whereby the rights-holder is held responsible for the actions of an employee) and one for stronger legal protection of Scottish Mountain Hares, collectively amassing over 85 000 signatures by 29 January 2016. To Recreational hunting of game birds and mammals is glob- date, however, wider environmental impacts of driven ally widespread (Loveridge 2009). Habitat and et al. grouse management have received little public scrutiny, predator management is sometimes undertaken to despite an increasing evidence base to inform a debate. increase game abundance and hunting bags (e.g. Hudson Here we assess environmental impacts of driven grouse 1992, Arroyo 2012). This can have environmental et al. management and consider current regulation and policy benefits such as creation and maintenance of wildlife-rich in the context of the objective of securing legal and envi- habitat (Potts 1986, Loveridge 2009), but may con- et al. ronmentally sustainable outcomes. flict with delivering other ecosystem services and public benefits from the same landscapes (Cot^ e et al. 2004). For these reasons, regulations to ensure responsible manage- THE ECOSYSTEM SERVICES OF ment and monitoring of game populations are widely MOORLAND HABITATS recommended (Loveridge et al. 2009, Caro et al. 2014). Here we consider management for recreational shoot- Red Grouse depend on moorland habitats comprising ing of Red Grouse Lagopus lagopus scotica, a subspecies blanket bog and heath beyond the altitudinal and of Willow Ptarmigan Lagopus lagopus that is endemic to climatic limits of enclosed agriculture (Watson & Moss submontane heathlands in the United Kingdom. The 2008). These habitats and the breeding bird assemblages non-lekking, monogamous, highly territorial Willow they support in the UK are of international conservation Ptarmigan has a circumpolar distribution typically occur- importance (Thompson et al. 1995), with large areas ring at low breeding densities (0.1À10 pairs per km2) protected under national and international law. Moor- across northern Europe, northern Eurasia and North lands also provide regulatory and cultural ecosystem ser- America (Watson & Moss 2008). However, in the UK vices. The UK uplands are landscapes that inspire intensive habitat management, predator control and med- millions of people, with associated benefits for local ication are used to secure exceptionally high (150À500 economies, health and well-being. They provide 70% of birds per km2) post-breeding densities of Red Grouse, drinking water in Britain, and support peatlands in Eng- which are then driven (flushed) over static lines of shoot- land and Scotland that are the largest carbon store in ers (Hudson 2008). This high-input, high-output man- the UK, amounting to almost 1800 Mt (Bonn et al. agement is practised in a regulatory environment in 2009, Chapman et al. 2009, Alonso et al. 2012). which landowners set their own bag limits and establish the management to deliver these, with the state only reg- RED GROUSE SHOOTING *Corresponding author. Driven shooting of Red Grouse on moorlands managed Email: [email protected] for the purpose is the economically dominant and most © 2016 British Ornithologists’ Union Environmental impacts of driven grouse shooting 447 prestigious form of gamebird shooting in the UK (Hud- sheep and deer and control of Bracken Pteridium aquil- son 1992, Sotherton et al. 2009). Grouse are driven by inum by herbicide spraying are also used to maintain lines of ‘beaters’ to fly over a row of shooters who Heather dominance (Grant et al. 2012). expect to kill more grouse in a day (30À40 each) than on a ‘walked-up’ shoot, where hunters walk in line using dogs to flush grouse. Most of this shooting takes place Treatment of grouse disease on private land. Red Grouse are vulnerable to strongylosis, a disease Fewer Red Grouse are now shot over a smaller land caused by the gastrointestinal nematode Trichostrongylus area than in the heyday of driven grouse shooting in the tenuis which depresses body condition, may cause death, early 20th century (Hudson 1992). However, grouse and can reduce brood sizes and population densities shooting still takes place over approximately 850 000 ha (Redpath et al. 2006). Following trials (Newborn & Fos- (Douglas et al. 2015), with the intensity of management ter 2002), Red Grouse are now routinely treated with (number of gamekeepers employed, vegetation burning anti-worming drugs (flubendazole) by medication of grit, and grouse medication) increasing over the last which the birds take to aid digestion of Heather. This 20À30 years (Natural England 2009, Clutterbuck & Yal- medicated grit, including ‘super-strength’ varieties lop 2010). This reflects an industry choosing to intensify (Osborne 2013), is dispensed from boxes typically further to meet perceived market demands, with eco- located 100À200 m apart across the moor (i.e. one box nomic returns apparently reliant on producing ever more per territory). Red Grouse are also susceptible to loup- grouse (Osborne 2013). Annual monitoring of post- ing-ill, a virus causing encephalomyelitis in sheep that is breeding Red Grouse densities by the GWCT on a sam- also carried by wild mammals such as hares and deer, 2 ple of moors shows a 90% increase from 171 per km and is transmitted by the tick Ixodes ricinus (Watson & 2 (1990À1994) to 325 per km (2010À2014) in England Moss 2008). To reduce the infection risk from louping- 2 and a 74% increase from 81 to 141 per km over the ill, some gamekeepers treat sheep with acaricides which same period in Scotland, with the rapid increase attribu- can reduce tick burdens by 90% and also shoot Moun- ted to higher strengths of medicated grit to combat tain Hares and Red Deer Cervus elaphus (Watson & strongyle worm infections in grouse (Game & Wildlife Moss 2008, Newborn & Baines 2012). Conservation Trust 2015). In places, Red Grouse are now more abundant than at any time since the 1930s (Osborne 2013). ENVIRONMENTAL IMPACTS OF MANAGEMENT PRACTICES GROUSE MANAGEMENT PRACTICES Predator control Predator control Control of corvids, foxes and mustelids can increase the breeding success and abundance of other ground-nesting Gamekeepers kill predators of grouse to maximize the birds, including Northern Lapwing Vanellus vanellus, shootable surplus. Red Foxes Vulpes vulpes, Stoats Mus- European Golden Plover Pluvialis apricaria and Eurasian tela erminea, Weasels Mustela nivalis and some corvid Curlew Numenius arquata (e.g. Tharme et al. 2001, Corvus species are legally shot and trapped. However, Fletcher et al. 2010), as well as Red Grouse. However, illegal trapping, shooting and poisoning of protected protected raptors, mammalian predators such as Wild- birds of prey and mammalian predators also takes place cats Felis silvestris, Badgers Meles meles, Pine Martens and limits the national range and population size of Martes martes and even domestic cats are regularly killed some species (Whitfield et al. 2003, Redpath et al. illegally (Harris & Yalden 2008, RSPB 2015). The 2010, Amar et al. 2012). impacts on raptors have received the most attention. For example, (1) illegal use of poisons to kill predators is associated Managed burning, grazing and vegetation with land actively managed for grouse shooting control (Whitfield et al. 2003); Red Grouse feed mainly on young, nutritious Heather (2) Hen Harriers are almost entirely absent from dri- Calluna vulgaris shoot tips and use older, deeper ven grouse moors across the UK, yet estimates Heather for nesting and protective cover. Vegetation is based on habitat area indicated there was sufficient burned on rotation (every 10À30 years) to create and habitat to support almost 500 pairs on driven maintain a mosaic of different ages of Heather and other grouse moors (Redpath et al. 2010); dwarf shrubs to benefit grouse (Hudson 1992). Managed (3) illegal killing of Golden Eagles Aquila chrysaetos and burning also maintains open habitats by inhibiting wood- Red Kites Milvus milvus in Scotland,