Subsequent to @Game Warden's response, I have decided to address various criticisms of grouse shooting while acknowledging that, insofar as predator control is concerned, there will those that will still find the comments relevant to this aspect of the subject to be less than satisfactory. I am somewhat time-constrained because I'm off to the Pantanal later in the month. I will therefore point out various useful sources of literature. For those who are seriously interested in the subject of driven grouse shooting and in understanding its place within the wider aspects of moorland management, I cannot recommend the website of The Moorland Association strongly enough. (I'm not au fait with the creation of links, but the website is easy to find by googling the organisation's title. Perhaps, if the debate goes further, someone who is more computer literate than I can provide a link.) For details of grouse research and, in particular, for consideration of the benefits of predator control, I would recommend visiting the relevant sections of the website of The Game and Wildlife Conservancy Trust, in particular their Langholm and Otterburn studies).
At the outset, I should explain that I can fully understand why those without rural roots might find the pastime of those who kill defenceless birds for pleasure to be repugnant. Countrymen tend to live within the natural (or, in the case of the UK, semi-natural) world and don't grow up with the death-denying culture of many townsmen who are outside observers of nature rather than living in it. Clearly, for those with animal rights beliefs, shooting pheasants for sport is scarcely less heinous than shooting peasants. I am not trying to change minds on this issue, but I am very much trying to convince potential critics that driven grouse shooting, on the whole, confers very substantial conservation benefits at minimal public cost. It is important to appreciate that the management required to produce a shootable surplus of grouse confers similar benefits to a suite of other non-target ground nesting bird species that are that are in steep decline in non-managed areas of moorland. A necessary part of the management package is control of those predators (vermin) that can legally be killed (foxes, corvids and small mustelids). Such species are widely represented by large populations and the local deaths of those which might impact adversely on grouse are of no conservation consequence.
The red grouse is endemic to the UK and it depends for its survival on heather moorland. The productivity of such moorland varies and hens on wet, blanket bog moors tend to lay larger clutches than those on the higher, drier moors to the east. There are somewhat over 200 driving moors within the UK, most of which lie in the north of England. While Scotland has a greater area of moorland, most has less potential productivity and, in consequence, can justify less gamekeeper effort. While grouse can be shot in these areas, they are less commonly driven and keepers often devote as much time to deer as to grouse management. The average top quality driven grouse moor is around 2000 ha in area. It is worth noting that well less than half of the moorland area that could be made driveable is, in fact, used for driving. The management required is expensive to implement and is usually only undertaken by people rich enough to put more into the enterprise than they can realistically expect to take out.
In spring, birds form territorial pairs in territories of roughly 1ha. In theory, a productive moor should thus hold 2000 pairs at the start of the breeding season. In practice, not all habitat is suitable and the actual numbers will be less (say, 1500 pairs). There is no point in trying to hold more birds than can find suitable territories. It is not unreasonable to expect a good breeding season to produce a quadrupling of total grouse numbers by the start of the shooting season. Theoretically, therefore, one might plan to shoot shoot three quarters of one's stock (4500 brace). However, this would be excessive because it doesn't allow for inevitable post shooting losses. The total bag for the season is planned in advance, such that numbers of days and/or size of bags/day are designed to leave adequate breeders for the following season. After an extreme adverse weather event or severe disease outbreak, shooting may be suspended altogether for one or even two years to allow rebuilding of stock, thus depriving the moor proprietor of any income.
Grouse productivity is determined by suitability of habitat, levels of predation and disease and by weather. Game keepers can influence the first three to the advantage of grouse, but can only use prayer to prevent adverse weather.
1) Heather replacement of relatively unproductive black grass. It is generally not appreciated that grouse moor proprietors typically
have little control of sheep numbers and grazing patterns. Commoners and crofters with grazing rights survive on the economic edge and are reliant on government subsidies. In the past, these were based on headage payments such that total sheep numbers became more important than productivity as expressed by lambing percentage. This encouraged overgrazing and, in winter, this can destroy heather and lead to its replacement with blackgrass. Fortunately, the nature of the subsidy system has been changed such that it no longer encourages habitat degradation and efforts to reverse the damage have increased.
2) Bracken eradication. Bracken is neither useful for livestock or grouse. In addition the thick mat of dead vegetation beneath a bracken stand enhances tick survival.
3) Grip-blocking. It used to be believed that drainage of blanket bog was beneficial to sheep and, to an extent, to grouse. Research has more recently demonstrated that enhanced run-off leads to peat erosion and sedimentation of draining rivers to the detriment of salmonids. The erosion also leads to deepening of the grips into which grouse chicks can fall without hope of escape. Wetter conditions also encourage cotton grass establishment. Cotton grass plays an important role in increasing clutch size.
4) Encouragement of sphagnum moss now that it is recognised as being important for carbon sequestration. Furthermore, grouse benefit from boggy patches because chicks in early life need high protein in their diets, which can be provided by the increased density of invertebrates in the of boggy areas.
1) As mentioned previously, the killing of "vermin" is of paramount importance in any attempt to produce a shootable surplus of grouse sufficient to allow driving. Without the income from shooters, good management wouldn't be affordable.
2) Illegal control of protected predators, almost exclusively raptors (eagles, harriers and peregrines). That a certain amount takes place is undeniable and understandable. However, the extent to which it takes place is impossible to assess. Its extent is almost inevitably exaggerated by antis and downplayed by the pro-side. I am aware,for example, that an RSPB official planted false evidence against a gamekeeper (frozen carcass in wrong stage of moult for the time that it was meant to have been found). I am also aware of undeclared killing by gamekeepers,with which I personally sympathise, but know many of you won't support. Perhaps, therefore, I could make a plea for compromise and accommodation, which, in my view, is perfectly possible. The raptors mentioned are all generalist predators that don't necessarily reduce in number when grouse numbers decline. When grouse numbers are reduced through bad weather or disease, circumstances arise which can create what is known as a "predator trap". This describes a situation in which low grouse numbers can never be recovered from. When grouse numbers are high, a limited number of raptors can be accommodated. Golden eagles, as far as I'm aware, have been very rare in England for well over a century, while white tailed eagles were not present in the UK for 150 years until they were re-introduced to north west Scotland, an area with very few grouse and no grouse shooting interests. Attempts are now being made to transfer others to the east where it plausible to believe that they could have devastating effects on grouse stocks. A pair of the smaller golden eagles is capable of of killing some 300 grouse a year in the absence of good sources of carrion (it should be noted that it is illegal for landowners and farmers to leave carrion lying about on their land). As some of the grouse killed will be potential breeding stock, one can assess the cost of a pair of golden eagles to the landowner to be in the region of the cost of employing one game keeper. In parts of Scotland, particularly those with marginal stocks of grouse, grouse moor management will become unaffordable and stocks of ground nesting species and hares will plunge in the absence of vermin control. It is ironic that hen harriers are, themselves, ground nesting, but they only really breed well on moors that are managed for grouse. However, they can themselves cause up to 20-30% of overwinter mortality in adult grouse as well as predating heavily on chicks. When their numbers rise to a level that makes sustainable grouse shooting impossible, keepers lose their jobs and foxes move back on to moorland and wipe out the harriers (see research conducted at Langholm). There are ways of addressing some of these conflicts, such as by diversionary feeding or translocation of raptors to new locations if their numbers become concentrated in a few. These suggestions involve cost and have been resisted by organisations such as the RSPB which seems willing to pour considerable funds into policing, but not to spend any members' money in managing moors for raptors rather than grouse (there is plenty of moorland for this to happen).
C) Significant diseases and their control.
1) Trichostrongylosis and its control. Caused by a nemotode parasite, spread by direct cycle, that accumulates in the caeca of grouse, reducing their laying potential or killing them. Other galliform birds tend to develop fairly rapid and robust immunity and don't suffer in the same way. This might suggest that this parasite has only found its way into grouse fairly recently in evolutionary terms. Grouse can be treated by individually dosing them by crop tube after the shooting season, having been dazzled and caught at night. Although this is a tedious and somewhat hazardous endeavour, it was nevertheless put into practice on many moors, giving an indication of both the damage that the disease can cause and the value of the individual grouse. Such dosing kills all worms present at the time it is carried out, but has no effects on stopping new worms from being picked up. Direct dosing has almost entirely been replaced with medicated quartz grit. Grit is typically placed in boxes in a grid pattern across the moor, ideally allowing one box/territory. It can be used as soon as the shooting season is over and must be removed 30 days before the start of the next. This ensures that no benzimidazole enters the human food chain. Environmental contamination will be confined to killing a few free living nematodes in the immediate vicinity of grouse faeces and gritting boxes. It should be noted that the Veterinary Medicines Directorate has licensed the drug for this use and, before doing so, environmental risks are assessed. Fairly recent improvements to drug concentrations on grit and coatings to weatherproof the product have dramatically improved grouse productivity and largely eliminated or dampened the population quasi-cycles that existed when the disease was rife.
2) Louping Ill and its control. An unusual virus disease in that several different host species can become infected (most viruses are fairly host specific). The infection is spread between hosts by ticks. If young grouse are infected, there will be a 75-80% mortality rate and survivors will be immune to re-infection. However, they won't pass on any useful passive immunity to their progeny. The principal source of virus is normally sheep. Sheep don't die of infection, but returning future breeders, having been reared on the low ground are susceptible and may abort. There is a vaccine available, but most graziers either can't afford or can't be bothered to use it (its cost benefit analysis isn't that obvious). On occasions, grouse proprietors buy vaccine on the graziers' behalf and, in addition, often supervise its administration to the sheep. Tick reduction is another approach to louping ill control. Unfortunately, the more effective long lasting dips, withdrawn for reasons of potential toxicity, have been replaced with those that are far shorter acting. Thus, the not inconsiderable effort of gathering moorland sheep to dip them has largely stopped. Some proprietors have acquired their own flocks and use them as so-called "tick mops". The sheep are rotated round the moor, picking up ticks as they go, and are repeatedly dipped. This requires far greater labour input than that required for a typical flock, hefted to a part of the hill, and largely allowed to get on with it without much human intervention. The third species that can become viraemic and multiply virus around tick bites is the mountain hare. This species is thus able to transmit infection (via ticks) to both grouse and sheep. Louping Ill virus is present only in the minority of driving moors. However, if one does have a moor which one is trying make productive for grouse and that moor has sheep, a high hare density and the the presence of virus, one has a severe problem of disease control. A few such moor owners have sought to eliminate (in practice, to greatly reduce the density) of their hares. This is a temporary cull which will stop, either when the virus is eliminated or when attempts to eliminate it and re-establish a sustainably harvestable stock of grouse have failed. I would like to emphasise that the mass killing of hares is undertaken as part of a disease eradication programme and not for any sporting reason.
I think I've banged on enough about process. I will conclude by suggesting that species protection is often inimical to good conservation and that obsessing over charismatic raptors at the expense of smaller species is unfortunate. I would further suggest that you can't have your cake and eat it off a single plate. However, if I were to be given the typical annual budget that grouse proprietors spend on their management, I could almost guarantee that I could generate enough raptors to keep bird watchers happy without ruining grouse interests.
I have not made point by point rebuttals to comments made in the lead post of this debate. I am sure the author will withdraw some of the criticisms, having gained a better understanding of the subject after he has studied the material to which I made reference. I am sure others will remain and I will be happy to address them. In passing, I should note that fence collisions are not the responsibility of grouse proprietors, but of foresters. I have not mentioned lead, but I have some evidence from my own research that suggests that it isn't of overwhelming importance in conservation terms, but may be worth discussing anyway.