CHAPTER 5
POPULATION MANAGEMENT AND CONTROL
5.1 Our terms of reference required us to consider the impact of hunting, and of a ban on hunting, on "agriculture and pest control and the management and conservation of wildlife". Chapter 6 discusses in greater detail the animal welfare issues that are associated with hunting and other methods of control. Chapter 7 addresses issues to do with the effect of hunting on the management and conservation of habitat and other wildlife. In this chapter we examine:
- the reasons which are put forward by farmers, foresters, game managers and others for managing the fox, deer, hare and mink population
- the methods that are used and their effectiveness
- the impact of hunting, and the effect of a ban, on the management of these populations
5.2 Our examination of these issues was helped by the research which we commissioned from two teams led by Professor David Macdonald and by Professor Stephen Harris. Both research reports1 2contain a wealth of information summarising evidence drawn from other recent research and surveys as well as other evidence submitted to us. In the following paragraphs we try to summarise the key points and to set out our own conclusions.
5.3 Before turning to a discussion of each of the quarry species, it is worth noting some of the cautionary points that need to be borne in mind in considering the management of animal populations, especially those which may be regarded as pests:
- the population of a particular species is naturally limited by the availability of critical resources such as food and breeding sites or by other factors such as predation and the weather3
- as a population approaches the maximum dictated by these factors, some form of self-regulation normally sets in. This can take the form, for example, of smaller litter sizes or the postponement of sexual maturity4
- there is no natural population "equilibrium level": it will depend on the prevailing combination of influences, including human intervention. It will also constantly alter as influencing factors change5
- the reasons for undertaking population management (which may be non-lethal or lethal) are many and varied. They include pest control, sport, food and conservation6
- these reasons may also be conflicting. For example, the brown hare can be viewed at the same time as a pest, a game animal and the subject of conservation action7
- human intervention in order to manage an animal population can take many forms, ranging from culling to non-lethal methods such as fencing or contraception8
- measuring the long-term impact of culling on a population is not straightforward
- culling does not necessarily produce a proportional decrease in abundance or damage: for example, other animals may move into vacant territory9 or birth rates may increase in response to lower population density; and damage may be caused by particular iniduals.10 It is therefore important to distinguish between attempted and achieved population control, and to bear in mind that a reduction in population does not necessarily translate into a pro rata reduction in a perceived problem
- culling needs to be carefully targeted if it is to achieve maximum impact.
Population
5.4 The pre-breeding fox population of England and Wales is thought to total some 217,000, but this estimate has a low reliability. The population almost trebles by the early summer.11 Local densities are highly variable, with historically low populations in East Anglia, although numbers now seem to be increasing there. Foxes live in pairs or groups of up to about 5 adult animals, generally comprising one adult male and several females. Usually only one or two females in each group breed. Cubs are born from March to May in litters of four or five.12
5.5 Unfortunately, there is very little information about the numbers of foxes which are deliberately killed each year and the methods used. Since the population approximately trebles after the breeding season, and on the basis that the pre-breeding population is roughly stable or increasing slightly, this means that about 400,000 foxes die each year.
5.6 There is no reliable information about how many die by different means. However, there is circumstantial evidence, from surveys of farmers, that deliberate culling is a substantial factor in this mortality.
5.7 There is also a corresponding lack of information about the proportion of foxes which are killed by the different culling methods. Generally, systematic records are those kept by the MFHA packs. However, a study of three contrasting areas does provide some information about the different culling practices in those areas.13
5.8 The study showed that, for upland Wales, the east Midlands and west Norfolk, respectively, 35%, 15% and 3% of foxes culled were killed by methods involving the foxhounds, whereas 10%, 3% and 7% involved digging-out with terriers outside the context of the hunt. The proportions for those shot with a rifle (including spot lamping) were 21%, 53% and 64%, and for shotguns (when foxes were driven, usually by hounds, onto standing guns) were 25%, 9% and 4%. Snares accounted for 3%, 13% and 9%. Just over half the foxes killed were in their second year.
5.9 In summary, in the upland area of Wales, terriers or hounds were involved in some way in the killing of 70% of the fox tally, but 27% and 14% in the east Midlands and west Norfolk.
Reasons for population management
5.10 Many farmers and landowners undertake fox control but there are regional variations in the numbers doing so.14 The only large-scale study which took account of culling by both the hunt and the inidual farmer estimated that foxes were culled on an average of 88% of farms across mid Wales, the east Midlands and west Norfolk.15 Although foxes are widely perceived as a pest, two studies suggested that rabbits, rather than foxes, were viewed as a more significant problem.16 17
5.11 The majority of farmers and landowners who do control foxes give several reasons for doing so. Of these, reducing fox abundance is the most frequently mentioned, generally to reduce predation on livestock and game. Foxes are also considered a pest because they are thought to transmit disease. There are considerable regional differences in the reasons for control.18 19 In general, more farmers in Wales cite protection of livestock (sheep) as a reason for culling foxes. In East Anglia foxes, where arable farming predominates, are perceived as less of a problem for livestock, but more of a problem for game, reflected in the large numbers of gamekeepers in the region.20 21 Surveys indicate that farmers in the Midlands often cite sport as a reason for killing foxes.22 23 Many farmers aim to contribute to regional control of fox populations. On farms larger than 200ha, an inidual farmer’s recent experiences of fox predation were surprisingly unrelated to their control measures, and there was evidence that farmers saw control as a preventative measure.24
Predation on lambs
5.12 The main concern centres on fox predation of lambs, especially in upland sheep- rearing areas where intensive husbandry is difficult and where a lower proportion of lambs (40% in mid-Wales) are born indoors.25 There is evidence that predation levels are generally higher in upland areas than in lowland areas.26 This probably reflects in part the tendency for more lambs to be born indoors in lowland areas.27 It may also reflect the relative health, condition and behaviour of ewes. It is not easy, however, to establish with any certainty how serious a problem fox predation represents. Predation is not usually witnessed; it is not always possible to distinguish between the killing of healthy lambs and scavenging dead or dying ones; and other predators, including domestic dogs, also kill lambs.28
5.13 In a study carried out by the Game Conservancy Trust in 1995-1997 the total reported pre-weaning losses which were attributed to foxes among all 522,422 lambs (indoor and outdoor) in mid-Wales was 3,134 lambs, amounting to 0.6%.29 As a proportion of outdoor lambs, the figure would be 1%. At a typical market price in 1996 of £31.50 per lamb the total regional loss of income would have been just under £100,000. Of course, the effect of the loss on an inidual farmer will vary, depending on his or her circumstances.
5.14 The best estimate seems to be that a low percentage (less than 2%) of otherwise viable lambs are killed by foxes in England and Wales.30 However, levels of predation (or perceived predation) can be highly variable between farms and between different areas.31
5.15 It is clear that only a small proportion of foxes kill lambs; otherwise, lamb losses would be much higher. It is widely believed by shepherds that certain foxes are more likely to take lambs, including vixens with cubs and old or injured animals. It is also argued that, once a fox starts taking lambs, it is likely to continue doing so.
Predation on poultry and piglets
5.16 Predation by foxes on poultry is potentially catastrophic because foxes can indulge in surplus killing.32 However, the vast majority of poultry are reared in secure indoor units and are not at risk.33 Predation is therefore almost entirely confined to the growing number of smaller, free-range holdings, where losses in large commercial flocks have been estimated to be about 2% a year34; losses in small (<200) flocks can be much greater. The NFU informed us that, whereas 86% of eggs came from intensive units in 1995, by 1999 this had fallen to 75% in favour of free range, perchery and other more extensive systems.35 The extent of losses varies regionally. Foxes can also cause loss of piglets, through predation and disturbance to sows; there has been no systematic study of this problem, but it is almost certainly growing, as numbers of outdoor units are increasing. The NFU report that some pig farmers with extensive outdoor systems report cases of pre-weaning deaths of over 25% directly attributable to foxes.36
Predation on game
5.17 It is clear that foxes kill a substantial number of game birds, both wild and hand-reared.37 38 Hand-reared pheasants are particularly vulnerable when they are released from their rearing pens.39 In the absence of fox control a substantial number of birds would be lost before the start of the shooting season. Wild pheasants, on the other hand, are particularly vulnerable during the breeding period. While there are other factors that affect pheasant populations, it is probably the case that foxes are the most significant predator affecting pheasant shooting.40 Foxes can also have an impact on partridge populations.41 42
5.18 It is thought that foxes are significant predators of grouse on commercial grouse moors in England and Wales.43
5.19 The impact of foxes on hare populations is also uncertain.44 Some studies suggest that the extent of predation has a substantial effect, while other studies are equivocal.45 46 The impact may also vary locally.
Predation on other ground-nesting birds
5.20 Many ground-nesting birds are potentially vulnerable to fox predation, particularly species such as terns which nest in colonies.47 This has proved a problem, especially on coastal bird reserves.48 Local conditions can, however, have a dramatic effect on rates of predation and other factors can affect the vulnerability of ground-nesting species.49
Transmission of disease
5.21 Foxes are potentially able to catch and transmit a number of parasitic infections, viral and bacterial diseases to companion animals, domestic stock and hunting dogs. However, although farmers often cite disease control as a motive for killing foxes, there is no clear evidence that foxes have been a significant contributory factor in any disease in this country.50
Culling for sport/pleasure
5.22 While the main motivation for culling foxes will often be for one or more of the reasons already mentioned, it is clear that for some people it is the pleasure gained from, for example, hunting, shooting or terrierwork.
Methods used
5.23 The following paragraphs describe the main methods used in attempts to manage the fox population. As we have already noted, no reliable information exists about their use at a national level, although it is clear that there are marked regional variations.
Lamping with a rifle
5.24 This method typically involves the use of a high-powered spot lamp at night, mounted on a vehicle. The fox is caught in the beam and shot with a rifle.51 Shotguns may also be used. Sometimes a 'squeaker' is employed to mimic a rabbit in order to bring the fox nearer. Efficient lamping requires good vehicular access. Its usefulness can therefore be limited in areas with rough terrain and steep slopes. It also requires terrain that allows safe shooting. Another limiting factor is the extent of vegetative cover. Lamping is most effective in autumn when fox densities are high, cover is reduced and the inexperience of young foxes makes them a relatively easy target.52
Shooting by day
5.25 This involves groups or iniduals shooting foxes, sometimes in driven shoots where beaters drive foxes from daytime rest to a line of waiting shotguns. It is common too for foxes to be shot at their earths, especially during the cubbing season. Terriers are often used to flush or locate foxes, so that they can be shot, and to kill cubs. Methods involving shooting probably account for over half the foxes killed by gamekeepers.
Hunting with hounds
5.26 We described in some detail the different forms of foxhunting in Chapter 2 of our report. The main types are hunting on horseback and on foot and the Welsh gunpacks, which use hounds to flush out foxes to waiting guns. MFHA-registered hunts account for some 14,000-15,000 foxes each year, although about a third of these are dug out. Upland foot and gun packs may account for 7,000-10,000 foxes; some foot packs may take a high proportion of their cull (about 60%) using terriers.
Digging-out/Terrierwork
5.27 As we mentioned in paragraphs 2.23 to 2.25, this method is widely used by foxhunts, gamekeepers and small groups or iniduals. It involves using terriers to locate the fox underground so that it can be dug out and shot.53 (As we have just noted, terriers are also sometimes used to bolt the fox so that it can be shot or pursued by dogs). Terrierwork seems to be particularly prevalent in Wales and other upland areas, either in association with organised foxhunting or by others.54 Including digging-out by the registered packs, over a third of the cull of foxes in mid-Wales is the result of terrierwork.55 Although terriers are widely used by gamekeepers, overall they appear to account for only a small proportion of foxes killed by them56 but the extent to which they are used to bolt foxes which are then shot is unknown.
Lamping with lurchers
5.28 This method of killing foxes involves the use of lurchers to chase and kill foxes which have been caught in the beam of a spotlamp (see paragraph 5.24 above). It is popular in certain areas but, because it is often carried out illegally, there are no reliable estimates of the numbers of foxes killed.57 58 59
Snares
5.29 Fox snares consist of a heavy wire loop set across an area where a fox is likely to pass, with the free end anchored. The loop is designed to hold the fox by the neck until it can be killed humanely.60 A legal snare must have a 'stop' in order to avoid strangulation. Snares are still widely used by gamekeepers,61 although there appears to have been a shift away from this method in favour of lamping with a rifle. The use of snares is unpopular in sheep-rearing country during the lambing season because of the risk of lambs being caught 62 and is not advisable near footpaths because of dogs. About half of the captures made by snares are of non-target species, but these are generally released alive.63
5.30 The Wildlife and Countryside Act 1981 prohibits the use of self-locking snares and the setting of snares in circumstances where they are likely to kill or injure protected species. BASC advises against setting snares where there are signs of badger; near footpaths, rights of way or in areas used regularly for exercising domestic animals; or where livestock are grazing or along fences of fields used for livestock grazing.64
Trapping
5.31 Fox traps typically comprise mesh cages that catch the fox alive until it can be killed humanely.65 Live-capture trapping is not widely used in rural areas since experience shows that it has limited success.66
Poisoning and gassing
5.32 Some instances of poisoning foxes still occur, although this practice is illegal. Gassing is also illegal in practice since there is no approved product which may be used. Foxes are sometimes killed, however, by using a hosepipe to direct exhaust fumes into an earth.
Non-lethal methods
5.33 Potential non-lethal methods of controlling foxes fall into three main categories:
- the use of contraceptives and abortifacients
- the use of conditioned taste aversion, repellents or ersionary feeding
- the use of methods such as fencing in order to protect livestock.67
5.34 The evidence we have received indicates that the first two of these methods are still essentially experimental and subject to a substantial number of practical difficulties. These include the problem of ensuring that a sufficiently high proportion of the target population is reached.68
5.35 The use of physical barriers such as fencing, especially electric fencing, can be effective in small areas but is not practicable on a wider scale.69 70
Effectiveness of the different methods
5.36 As we have already noted, there is a lack of firm information about the extent to which the different methods of control are used. However, the research which we have commissioned from the two research teams reaches very similar conclusions about the effectiveness of the different methods:
- killing with dogs, in its various forms, accounts for a substantial proportion of the numbers of foxes killed
- shooting, however, has a much greater capacity to reduce fox populations
- the overall contribution of traditional foxhunting, within the overall total of control techniques involving dogs, is almost certainly insignificant in terms of the management of the fox population as a whole
- but there are clear regional variations in the importance of the different culling methods, and hunting by the registered and unregistered packs may have an effect in some locations, especially in sheep-rearing upland areas
- population modelling indicates that the main impact on population stems from culling adults and sub-adults, rather than cubs
- culling cubs has no significant effect on the longer-term population unless it reaches very high levels
- culling foxes does not necessarily have a pro rata effect on the problem or perceived problem.
5.37 Although the present impact of the registered packs on managing the fox population may be minor, other than in upland areas such as mid-Wales, it is much harder to predict the effect of a ban. Not everyone accepts that it is necessary to manage the fox population: some argue that it would be satisfactory to rely on natural self-regulation. It is clear, however, that the great majority of land managers do consider it necessary. Given that farmers and others presently do not have to pay the hunts for their efforts in seeking to control the numbers of foxes, there must be a risk that, faced with the prospect of paying for fox control, they would be more willing to allow culling by those who lack expertise. Moreover, there is evidence that farmers consistently over-estimate the numbers of foxes killed by hunts.71 This could therefore lead, in the absence of a ban, to their killing more than are actually killed by the hunts. It is clear, too, that some farmers and landowners presently tolerate foxes because of their own support for hunting. If hunting was banned, and the numbers of foxes increased, it is likely that there would be less tolerance of foxes. Finally, there is the issue of the extent to which those who presently engage in non-registered or illegal hunting would comply with a ban.
5.38 It seems probable that a ban on hunting would lead to some increase in shooting and snaring, in response to actual or perceived increases in fox numbers. We discuss in the next chapter their relative acceptability in terms of animal welfare. It is worth noting, however, that lamping has its limitations. It can be time-consuming, is not always suited to the terrain and night shooting can give rise to concern on the part of those living in the area.
5.39 Other means of fox control, in particular shooting, seem capable of killing at least as many foxes as are killed by hunting, except in mid-Wales and some other upland areas. In mid-Wales, methods involving dogs are currently effective in maintaining the population below carrying capacity and cost very little. In the event of a ban, shooting would be the most viable alternative but even this would be difficult because of the terrain.72 Much would depend, in upland areas, on whether it was still permissible to use dogs to flush foxes to guns.
Conclusions
5.40 In most areas of England and Wales farmers, landowners and gamekeepers consider that it is necessary to manage fox populations in view of the damage which foxes can cause to farming and game management interests.
5.41 Methods involving guns probably account for the greater part of those foxes which are deliberately killed, but there are marked regional variations.
5.42 In lowland areas hunting by the registered packs makes only a minor contribution to the management of the fox population, and terrierwork, especially by gamekeepers, may be more important. In these areas, in the event of a ban, other means of control have the potential to replace the hunts' role in culling foxes.
5.43 In upland areas, where the fox population causes more damage to sheep-rearing and game management interests, and where there is a greater perceived need for control, fewer alternatives are available to the use of dogs, either to flush out to guns or for digging-out.
Deer
Population
5.44 Six species of deer occur in the wild in England and Wales. Of these, only two, roe and red, are indigenous. The remaining species, fallow, sika, muntjac and Chinese water deer, were deliberately introduced for hunting or as wildlife curiosities.73 Of the six species, only one - red deer - is hunted with dogs by registered packs, although there are a small number of unregistered packs hunting roe deer, and fallow deer were hunted in the New Forest as recently as 1997.74 In the following paragraphs we concentrate on red deer, since it is this species which is primarily involved.
5.45 Red deer populations are localised in England and Wales. Their numbers increased rapidly in the 1970s and 1980s. There are estimated to be some 12,500 wild red deer in England and Wales, some 10,000 of which are found in the south west of England, with 4,000-6,000 within the staghunting countries, mainly on Exmoor, the Quantocks and in mid-Devon.75 76 It is estimated that about 1,000 deer need to be killed each year in the areas covered by the three hunts in order to maintain a stable population.
5.46 Red deer are found in a great ersity of habitats, but the great majority of those in the south west of England frequent wooded valleys and surrounding farmland. They are versatile feeders, eating mainly grass but also browsing on tree shoots, shrubs, sedges, rushes and heather.77
5.47 Red deer are social animals but males and females are segregated for much of the year. Herds tend to be larger on open moorland, with groups of up to 40 not uncommon on Exmoor and the Quantocks. Mating occurs between September and October, with births from late May to early June. Calves (nearly always one) are weaned at 6-10 months. Sexual maturity depends on habitat quality, reflected in the varying proportion of hinds which conceive as yearlings. Mortality is highest in calves under 10 months old.78
Reasons for population management
5.48 In contrast to foxes and hares, there is virtually unanimous agreement that red deer populations - at least those of any size - need to be managed, mainly because of the damage which they cause to agricultural, forestry and conservation interests, coupled with the fact that populations are currently increasing.79 We will therefore describe only briefly the main reasons why population management is considered necessary before turning to the effectiveness of the different available methods.
Damage to agriculture
5.49 While there is not great concern about agricultural damage by red deer on a national scale, it is clear that it can be locally significant, especially in the south west of England.80 The main types of damage are to:
- cereal and other arable crops such as oilseed rape, especially once the ears have formed and the scope for compensatory growth is limited 81 82
- field crops such as peas and beans, through rolling or trampling83
- root crops, particularly when they are standing over winter84
- grassland through grazing and trampling85
- farm woodlands, through browsing on buds, foliage or shoots86
- walls, fences, hedges and banks.87 88
5.50 In the Quantocks, three-quarters of landholders (most being farmers) considered that red deer caused significant damage on their land.89 Median annual losses due to deer were estimated at around £500 per holding, but estimating the cost of damage is difficult and such estimates are known to be frequently inaccurate.90
Damage to forestry
5.51 The damage which red deer (and other deer species) cause to commercial forests and other woodland is the most important reason for controlling their numbers.91 The main causes of damage are by:
- browsing the shoots, particularly the leading shoots, of young trees92 93 94
- bark stripping - either to eat or as the result of "fraying" or "thrashing" (rubbing antlers to remove their velvet cover or to mark territory) 95 96 97
- browsing the forest floor and preventing regeneration.98
Damage to conservation interests
5.52 Deer grazing and browsing can, in some circumstances, be beneficial to conservation interests99 but the rapid increase in deer numbers has led to problems.100 101
As already noted, it can inhibit natural woodland regeneration: in particular, it can have the effect of removing the "middle" layer in woodland, with knock-on effects for other animals and predators.102 It can also prevent or impede coppice regrowth, which can adversely affect the habitat for many other species, including some butterflies.
Stalking and sale of venison
5.53 The income to be gained from letting stalking (for recreation) rights and the sale of venison are also reasons why red deer numbers are managed.103
Road traffic accidents
5.54 There is concern too about the number of road traffic accidents involving deer of all kinds. It was recently estimated that some 40,000 deer-related road traffic accidents occur each year in the UK, a few of which result in the deaths of the people involved.104
Methods used
5.55 There are only two methods used to cull red deer: shooting and hunting with dogs. There are also a number of non-lethal methods used to prevent damage by deer.
Hunting with hounds
5.56 We described in Chapter 2 the way in which red deer are hunted by the three registered packs in the south west of England.
Shooting/stalking
5.57 Shooting by stalking with a rifle or large bore shotgun is the most common method used throughout England and Wales, as well as in Scotland and in Northern Ireland. Smooth bore guns may be used legally only as slaughtering instruments (as used by the hunts) or for humane dispatch of severely injured deer or if shown to be necessary for the protection of cultivated land, pasture or enclosed woodland.105
5.58 Rifle culls tend to be taken either from an elevated platform, which helps to ensure a safe backdrop, or by stalking at ground level. Many deer stalkers use a dog to help them find a deer or to track or retrieve a deer which has been shot and injured, fatally or otherwise.106
Non-lethal methods
5.59 The main non-lethal methods used for preventing damage by red deer are:
- fencing - permanent or temporary fencing is used to exclude deer from forest plantations, agricultural fields, conservation areas and motorways 107 108
- tree shelters and guards - "growing tubes" are used to protect young trees, especially in small plantations 109 110
- habitat modification and ersionary feeding - for example, planting early-maturing grass to ert deer from nearby agricultural crops.111
5.60 Live capture of wild deer is illegal in England and Wales (but not in Scotland) except under special licence.112 No existing chemical repellent has yet proved to be effective.113 114 Fertility control by immuno-contraception is effective in principle but it is difficult to apply in practice and there are doubts about potential side effects and impact on other animals.115 116
Effectiveness of the different methods
5.61 As in the case of foxes, the two research reports which we commissioned reached very similar conclusions about the effectiveness of the different methods of controlling red deer.
Hunting with dogs
5.62 As we have noted earlier, about 1,000 deer need to be culled each year in the area covered by the three staghunts. The packs have hunted and killed about 160 deer each season over the last 5 years. (They also deal with around 80 additional casualties each year but these animals would probably have died anyway).117 This contributes only 15% of the total cull required to prevent further population increases within the hunt countries and contributes, therefore, considerably less to regional control.118 Practical considerations such as the available number of days for hunting, and its inherent inefficiency - kills are made only about half the days on which hunting takes place119 - make it unlikely that hunting's contribution to the overall cull could increase substantially. Another difficulty with relying on hunting as a population management strategy is that it is not sufficiently biased towards culling hinds and calves to achieve the desired reduction in overall numbers.120
5.63 It is also commonly argued that a secondary contribution made by the hunts to deer management is in dispersing groups of red deer which may be causing particular problems to a farmer or landowner.121 However, census work and observation of deer suggest that any dispersal effect is only very temporary, although this may be affected by the frequency of disturbance and the extent of nearby cover.122 123
Shooting
5.64 As already noted, shooting/stalking is by far the most important method used to reduce red deer numbers in England and Wales, as in the rest of Europe,124 and accounts for the great majority of deer killed in the staghunting area.
Non-lethal methods
5.65 It is reported that, while fencing can be effective (at a considerable cost) in excluding deer from relatively small areas, it is unsatisfactory as a means of excluding them from large areas (>200 ha) over long periods of time.125 Inidual tree protection is generally cheaper than fencing on areas less than 2-5 ha. Total exclusion of deer can also have a negative effect on the richness of plant, insect, bird and animal life and can discourage enjoyment of the countryside.126
5.66 In short, while methods such as fencing and tree guards are a useful part of an overall deer management strategy, they cannot obviate the need, in the south west of England - and, for that matter, in other areas - to carry out substantial culling in order to control population numbers.127
Impact of a ban on hunting
5.67 We noted in paragraph 5.62 that, in terms of the numbers of deer killed, hunting makes only a relatively small contribution to deer management in the south west of England.
5.68 It is sometimes argued that, because of the nature of the terrain in this area and its use by walkers and others, it would not be possible safely to rely solely on stalking as a means of culling deer there. However, we have seen no convincing reason why stalking could not operate efficiently in this area. And the numbers of deer killed by the hunts could, in our view, be made up fairly easily by licensed deer stalkers in the area.128 As evidence given to us by BASC points out, both the Deer Initiative and the BDS/BASC Code of Practice state that ‘culling must be carried out safely, legally and humanely’. A system of voluntary qualifications has been introduced through Deer Management Qualifications Ltd. These qualifications – The Deer Stalking Certificate Levels 1 and 2 - enable deerstalkers to demonstrate that they have the necessary theoretical knowledge and practical skill.129
5.69 However, one of the main arguments that the hunts advance in favour of hunting is that, because of the support which it undoubtedly enjoys from many farmers and landowners in the area, there is a much greater tolerance of deer than would otherwise be the case. It is said that, in the event of a ban on hunting, this "community of interest" would break down, resulting in a substantial reduction, or even extermination, of the red deer population through legal and illegal shooting. This would also lead, it is said, to many more deer being injured and to the deer becoming wary of people, thus reducing their attraction to visitors and others.
5.70 It is very difficult to predict accurately what inidual landowners would do in the event of a ban.130 131 The majority of land is owned by private farmers and some undoubtedly would seek to reduce the numbers on their land. The National Trust owns 10% of Exmoor National Park and retains shooting rights. We note that the ban on National Trust land has led to disagreements between the Trust and its tenants on appropriate management strategies, as is apparent from evidence supplied to us by the Holnicote Estate Farm Tenants' Association.132
5.71 Much would depend on the extent to which the "community of interest" which the hunts presently foster in managing the deer population could be replaced by an effective deer management strategy. The Exmoor Society, which told us that it holds no view on whether or not deer hunting should continue, argues strongly that a ban on hunting would require an “overall culling management system”.133 It suggests that the abolition of a key part of the current voluntary system would be so drastic “that it is simply unacceptable to ‘hope’ that a culling control system equally environmentally friendly (to the deer's existence) will just evolve; rather, it will have to be put in place.” This view is supported by the British Deer Society, which concludes that “in the absence of any form of controlling body with responsibility for co-ordinating the management of the red deer, deer numbers will decline as landowners follow their own agenda”.134 The BDS suggests the formation of a Deer Commission for England. The Government, through the Forestry Commission, already sponsors the Deer Initiative, and a Welsh Deer Initiative is also being developed. The Deer Initiative is a partnership between government agencies and non-governmental organisations, including MAFF, DETR, RSPCA, English Nature, CLA and BASC, seeking to encourage good deer management through local deer management groups.135 An Exmoor and District Deer Management Society already exists. The Society suggests that the community of interest would be seriously compromised by a ban on hunting. South West Deer Protection, an anti-hunting group, argues that existing deer management groups on Exmoor and the Quantocks are not likely to be successful. It urges the need for stronger controls, including a mandatory carcass tagging scheme for wild deer, a Deer Commission and deer wardens.
5.72 It seems probable that, in the event of a ban, the overall numbers of deer in the hunted area might decline somewhat but whether this would be to the extent that would lead to calls for action, such as a ban on shooting, cannot easily be foreseen.136
5.73 A possible decline in red deer in the staghunting countries means that farmers and foresters are unlikely to suffer from increased damage because of a ban. Visibility, which is important to the amenity value of deer, is not simply related to abundance, but also to the proportion of the time they spend hidden in cover.137
5.74 The redistribution of red deer within their ranges is another potentially important change which might arise from a greater reliance on stalking; this might lead to changes in browsing and grazing pressures and reduce the visibility of the deer in some areas.138
Conclusions
5.75 It is generally accepted that red deer numbers in Devon and Somerset need to be controlled. Hunting with dogs presently accounts for about 15% of the annual cull needed to maintain the population at its present level. However, because of the widespread support which it enjoys, and consequent tolerance by farmers of deer, hunting at present makes a significant contribution to management of the deer population in this area. In the event of a ban, some overall reduction in total deer numbers might occur unless an effective deer management strategy was implemented, which was capable of promoting the present collective interest in the management of deer and harnessing such interest into sound conservation management.
Hares
Population
5.76 There are two species of hare in Britain: the brown hare and the mountain hare. Brown hares are widespread throughout lowland Britain but their distribution is very patchy. They are scarce in much of Wales and the west country but abundant in many parts of East Anglia. This seems to reflect regional difference in habitat and farming activities. Mountain hares are almost entirely found in Scotland.139 Since hunting or coursing of hares in England and Wales is almost exclusively confined to brown hares, the following paragraphs deal entirely with this species.140
5.77 In the early 1990s there were thought to be about 630,250 hares in England and Wales and a further 187,250 in Scotland.141 Game bag records indicate a significant decline in numbers in Britain during the 1960s and 1970s, probably due, at least in part, to modern arable farming methods, particularly agricultural intensification and changing farming practices which have reduced the ersity of food available to hares year round. The hare is now included as a UK Bioersity Action Plan Species on the short list. However, hares are still locally common, and records from game bags and hunting records (from beagling) indicate that, nationally, numbers have been stable since 1983. The second national hare survey in the late 1990s estimated a national population of 752,608, but it is not clear whether this represents a decline.142 Hare populations can fluctuate considerably from year to year.
5.78 Hares breed from February through to October and occasionally in winter. Litters of up to three leverets are left inidually in scrapes; are tended by the female only; and are usually weaned at about three weeks old.143
5.79 There is a rapid turnover in population. Apart from natural mortality, through disease and poor nutrition, death results from numerous other causes, including predation by foxes, agricultural machinery and road casualties.144
Reasons for population management
5.80 As we have already noted, hares are simultaneously regarded as a pest by some farmers and foresters, as game and as a subject for conservation.145 This complicates - and leads to conflict in - the management of their population.
Damage to agriculture and forestry
5.81 Hares eat crops such as oilseed rape and turnip, and particularly grasses and cereals. In addition, hares can eat high value market garden crops, and will often kill newly-planted young trees and shrubs. Some of this damage can be of economic significance to inidual growers.146 In livestock areas hares are not numerous and are rarely considered a pest. In arable areas high numbers of hares on winter corn are considered damaging by most cereal farmers and regular winter culls by shooting are undertaken where this occurs.147
Shooting
5.82 In some parts of England, especially East Anglia, hare numbers are maintained at high levels for organised shooting.
Deterring poaching
5.83 Conversely, landowners may shoot hares in order to deter poaching and coursing. There is evidence that gangs of poachers are a particular problem in parts of Lincolnshire and East Anglia.
Coursing
5.84 In areas where coursing by the registered coursing clubs takes place high numbers of hares are encouraged and action is sometimes taken to re-populate hares by importing them from elsewhere.148 We received anecdotal evidence that, in the past at least, this has happened on quite a substantial basis. We discuss this matter further in Chapter 7.
Methods used
Shooting
5.85 Hare shooting is the means most frequently used by farmers in arable areas for pest control.149 It is estimated that some 200,000-300,000 hares are shot in Britain each year. Apart from ad hoc shooting, hare shoots are commonly organised in February. These normally take place over one or two farms. They consist of a series of drives, with participants shooting hares as they are flushed forward or as they try to break through one of the lines of guns.150 Hundreds of hares may be shot in a day.
Hunting and coursing
5.86 We described in Chapter 2 of our report the hunting of hares by the registered harrier, basset and beagle packs, and hare coursing by the registered coursing clubs and others.
Other methods
5.87 Hares are also snared and netted. Fencing and tree guards are used to protect trees against hares (and other species). Chemical repellents, habitat modification and scarers are not widely used to limit hare damage in Britain.
Effectiveness of the different methods
Shooting
5.88 There is no doubt that shooting is an effective means of reducing hare numbers, especially if carried out in the form of hare shoots. One piece of research estimated that hare shoots on four farms reduced hare numbers by an average of 50%.151 Population modelling suggests, however, that, because of the hare's reproductive potential, even killing a large proportion of adults or sub-adults would not have a long-term effect on hare populations.152
Hunting and coursing
5.89 No-one argues that legal hunting or coursing has an appreciable effect on hare numbers. The AMHB and the MBHA told us that, on average, about 5% of hares seen during a day's hunting are killed and that in the 1998/1999 season the packs killed some 1,650 hares.153
5.90 Similarly, legal hare coursing has a negligible impact on hare numbers. The average number killed at official hare coursing events are reported as being some 250 a year.154 As we noted in paragraph 2.56, however, many more hares are killed through other forms of coursing.
Impact of a ban on hunting/coursing
5.91 It is obvious from what we have just said that a ban on legal hunting and coursing would have no direct impact in practice on hare numbers.
5.92 What is more difficult to assess is the extent to which, in the absence of legal hunting and coursing, hare numbers would be adversely affected by:
- reduced tolerance by farmers of damage to agricultural crops
- less interest in encouraging and sustaining suitable habitats (see Chapter 7)
- greater propensity to allow shooting
- an increase in illegal coursing
- deliberate culling of hares to prevent illegal coursing.
5.93 There is no doubt that, in some areas at present, hare numbers are maintained at high levels for shooting and hunting/coursing purposes. It seems likely, in our view, that, in some of those areas at least, the hare population, in the event of a ban, would be lower than it is now.
Conclusions
5.94 There is little or no need to control overall hare numbers and, indeed, they are a Bioersity Action Plan species. However, the distribution of hares is uneven: they are abundant in some areas, mainly in the east of England, and scarce in much of Wales and the West Country. Hare hunting and coursing are essentially carried out for recreational purposes and have a relatively small direct impact on hare numbers. A ban would therefore have little effect in practice on agriculture or other interests.
5.95 Because hare numbers tend to be maintained at high levels in areas where hunting/coursing occurs, the impact of a ban might well be that, in the absence of other changes, the population would decline in those areas. This would partly result from a loss of suitable habitat but also, in a few areas, from the shooting of hares to deter poaching and illegal coursing. However, in comparison with the impact of organised shooting on hare numbers, a ban on hare hunting and coursing would have a negligible effect.
Mink
Population
5.96 As we noted in paragraph 2.59, mink were not introduced to this country until the 1920s. They were first confirmed breeding in the wild in 1956 in Devon and are now widespread throughout Britain, with relatively high densities in south west England, west Wales and west Scotland.155
5.97 Following an initial rapid increase in the population, there is now evidence that mink numbers have reduced substantially in the last ten years. This seems to have coincided with a resurgence in the otter population. The total population of mink in England and Wales is now thought to be some 18,000.
5.98 Mink are usually found near fresh water, but they also favour some coastal habitats. They are opportunistic, generalist predators, eating a wide range of mammals, birds, fish and invertebrates, their diets varying according to habitat and the time of the year.156 157 Common food items are rabbits, water birds and fish.158 Mink tend to be most active at night and during twilight hours.
5.99 Because mink have a very varied diet the risk to a particular prey species of extinction is much greater than where a predator specialises on a particular prey. This is because the automatic checks on predator numbers that would normally emerge as the prey species become scarce do not apply.
5.100 Mink climb well and their dens may be above ground in scrub or brush piles, or among tree roots, stones, in a hollow tree or in a rabbit burrow. There are several dens within one home range, most being close to water.159
5.101 Mink are largely solitary. Mating occurs between January and March. The kits, usually 3-6, are born between the end of April and mid-May. The young are weaned at 5-6 weeks and are cared for by the female only. Mink have no natural predators in Britain and significant mortality is caused by man.160
Reasons for population management
Predation on poultry and game birds
5.102 There have been many reported instances of mink killing domestic poultry, ducks and geese, along with ornamental wildfowl and game birds.161 Although the overall numbers, and financial loss, are relatively small, mink can indulge in surplus killing. The cost of predation on ornamental wildfowl collections and breeding stock can therefore be high in inidual cases.
Predation on fish
5.103 Fish, including salmon and trout, make up a substantial proportion of the diets of mink feeding on waters where they are available. Fish farms and fisheries are therefore potentially at risk. Although there have been instances when this has led to problems,162 there is little evidence that mink have had a significant effect on fish stocks and angling interests.163 164
Predation on wild birds
5.104 Birds may make up as much as 30% of the mink's diet and predation is especially high in the summer when fledglings and young water fowl are vulnerable.165 Mink have been directly linked to a decline in moorhens, coots and little grebes: moorhens and coots often represent as much as 80% of the birds eaten by mink on lowland waterways.166 167 However, evidence for an impact on coot is more compelling than for that on moorhens, illustrating subtle differences even between similar species. Furthermore, there is evidence that the numbers taken depend on these birds' relative abundance compared with other prey in a particular locality.168
5.105 Mink can be very troublesome in the case of ground-nesting seabirds, especially in Scotland and on small islands. Their activities, including surplus killing, have been linked to almost complete breeding failure amongst some colonies of terns and gulls, including some rare species.169
Predation on wild animals
5.106 While rabbits, where available, are the animal on which mink in Britain prey most frequently, they also eat substantial numbers of water voles. Mink have been held to be responsible for a major decline in water vole numbers: the population is thought to have fallen by some 80% in the last 10 years or so170. The evidence seems to be, however, that water vole populations were already in a general state of decline before mink became widespread, but that mink predation has had an especially severe effect on their already depleted numbers, leading to a risk of local extermination.171 172 Water voles are protected under Schedule 5 to the Wildlife and Countryside Act 1981.
Otters
5.107 Mink were initially held responsible for the decline of otters in the 1960s. Research shows, however, that this decline was, on the contrary, caused by the introduction in 1955 of organochlorine insecticides, dieldrin and aldrin, for use in sheep dip and seed dressings. Mink expanded rapidly as they moved into vacant territory. Mink and otter do compete for food resources but, when alternative prey such as rabbits are available, mink become more generalist predators to avoid competition with the otter.173 The recent resurgence in the otter population confirms that mink will tend to give way to otters.
Methods used and their effectiveness
Lethal methods
5.108 There are three lethal methods used to control mink:
- trapping
- shooting
- hunting with dogs.
Trapping
5.109 Trapping is recognised as the main method of controlling mink and is widely used by gamekeepers, water bailiffs, farmers and others.174 There are no firm data on the numbers of mink killed by trapping but research shows that intensive trapping in an area can remove most of the local population.175
5.11 Two types of trap are used: cage or tunnel traps, in which mink are captured alive and then shot, and spring traps, which are designed to break the neck of the mink.176 177
5.111 Mink do not appear to be particularly trap-shy and trapping can therefore be a relatively efficient means of control provided that the trap is well placed.178 Trapping success varies at different times of year, depending on the relative mobility of the sexes. Preventative trapping is most effective when it removes pregnant females in spring and territorial residents in the autumn once dispersal is largely finished.179 180
5.112 There does not seem to be any marked difference in the effectiveness of the two kinds of traps. Cage traps have the advantage that they enable non-target animals to be released unharmed. On the other hand, they have to be checked daily.181 182
Shooting
5.113 Shooting mink is carried out on an ad hoc basis by farmers and others, often incidentally to other shooting.
Hunting with dogs
5.114 We described in paragraphs 2.59 – 2.61 the way in which mink hunting is carried out by the 20 packs in England and Wales.
5.115 Mink hunts account for some 400-1400 mink a year.183 Packs catch an average of less than one mink per day's hunting, and the majority of mink found by the hounds evade capture, usually taking refuge in rocks or under trees.184
Non-lethal methods
5.116 Fencing can be an effective means of preventing mink from causing damage.185 Other techniques such as chemical repellents, habitat modification and fertility control have not been used.186
Impact of a ban on hunting
5.117 The Masters of Minkhounds Association recognises that hunting alone is not a sufficient means of controlling mink populations and that it has to be used alongside other control methods. It is clear that the contribution made by mink hunts to the control of mink populations nationally is insignificant. The numbers killed are far too low to make any impact on population numbers, especially given the high fecundity of mink.187 Moreover, hunting does not target the pre-breeding population of mink: those mink killed from mid-summer onwards are mainly pre-dispersal juveniles, many of whom would not have become adult territory-holders.188
5.119 A mink hunt may be successful in temporarily reducing mink numbers and breeding activity but any reductions may be compensated for quickly by other animals moving in. The hunt may be helpful to the farmer, though, in providing a free service and may be able to confirm the presence of mink, or locate it, even if they do not succeed in killing it.189
5.120 Set against this benefit, however, is the concern that hunting in areas where otters and mink coexist may disturb otters and prevent them from recolonising areas where they are scarce.190 Hunting may also cause disturbance to other birds and animals, especially during the breeding season, and cause damage to river banks and vegetation. 191
Conclusions
5.121 Mink can cause localised damage to poultry, gamebirds, fishing and wildlife interests. Because mink hunts kill relatively small numbers of mink, and because of their high fecundity and ability to disperse, hunting does not have any significant effect on the mink population at a national or regional level. It can, however, lead to temporary reductions in the mink population in specific localities.
5.122 Trapping is potentially an effective means of control but it needs to be carried out fairly intensively from January to April every year to have a lasting impact. It is therefore relatively costly. Hunting can be helpful in providing a free service to farmers and others that identifies where mink are located, enabling them to target trapping efforts more effectively.
1 Management and Control of Populations of Foxes, Deer, Hares, and Mink in England and Wales, and the Impact of Hunting with Dogs. Macdonald, D.W.1 Tattersall, F.H. 1 ,Johnson, P.J. 1,Carbone, C. 1, Reynolds, J.C. 2 , Langbein, J. 3 , Rushton, S.P. 4 and Shirley, M.D.F. 4 1 Wildlife Conservation Research Unit, Dept. of Zoology, South Parks Rd., Oxford, OX1 3PS; 2 The Game Conservancy Trust, Fordingbridge, Hampshire SP6 1EF; 3Wildlife Research Consultant, “Greenleas”, Chapel Cleeve, Minehead, Somerset TA24 6HY;4 Centre for Land Use and Water Resources Research, University of Newcastle Upon Tyne, Porter Building, Newcastle Upon Tyne NE1 7RU
2 Management of the Population of Foxes, Deer, Hares and Mink and the Impact of Hunting with Dogs. Piran White1 ,Philip Baker 2,Geraldine Newton Cross 1 , James Smart 1, Rebecca Moberly 1, Graeme McLaren 3,Rachel Ansell 2, and Stephen Harris 2 1Environment Department, University of York, Heslington, York YO1 5DD, 2School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG,3Myerscough College, Bilsborrow, Preston, Lancashire PR3 ORY.
3Macdonald et al, 1.3.2
4 Ibid, 1.3.2; 1.3.2.a.b
5 Ibid, 1.3.2
6 Ibid, 1.3.1
7 Ibid, 2.4
8 Ibid, 1.3.1
9 Ibid, 1.3.4.a; 1.3.4.b
10Ibid, 2.2.1.b
11 Ibid,5.2.7.a
12 Ibid, 10.1.4
13 Heydon and Reynolds, Table 11. 2000A
14 White et al,1.4.1.3
15 Macdonald et al, 3.2.6.B.1
16 White et al,4.1.4
17 Macdonald et al, 2.2.1.b
18 White et al, 1.4.1.5
19 Macdonald et al, 2.2.1.f
20 White et al, 1.4.1.5
21 Macdonald et al, 2.2.1.b
22 White et al, 1.4.1.5
23 Macdonald et al, 2.2.1.f
24 Ibid, 2.2.1.C
25 Ibid, 2.2.1.C
26 Ibid,1.4.2.1.1
27 Ibid,1.4.2.1.1
28 Macdonald et al, 2.2.1.c.i
29 Ibid, 2.2.1.c.i
30 Ibid, 2.2.1.c.i
31 White et al, 1.4.2.1.1
32 Ibid,1.4.2.1.c
33 Ibid,1.4.2.1.2
34 Ibid, 1.4.2.1.2
35 NFU of England and Wales 2, un-numbered
36 Ibid, un-numbered
37 Macdonald et al, 2.2.2.b; 2.2.2.C
38 White et al, 1.4.2.2.1
39 Ibid,1.4.2.2.1
40 Ibid,1.4.2.2.1
41 Ibid, 1.4.2.2.2
42 Macdonald et al, 2.2.2.b
43 White et al,1.4.2.2.3
44 Ibid,1.4.2.2.4
45 Ibid,1.4.2.2.4
46 Macdonald et al,2.2.2d
47 White et al,1.4.2.3
48 Macdonald et al, 2.2.3
49 White et al, 1.4.2.3
50 Ibid,1.4.2.4.5
51 A calibre .222 or larger is recommended in order to minimise wounding
52 White et al, 2.1.1.1.1
53 Macdonald et al, 3.2.2.c
54 Ibid,5.2.4,a; 5.2.5
55 Fox (vulpes vulpes) management in three contrasting regions of Britain in relation to agricultural and
sporting interests. Journal of Zoology 251. Heydon and Reynolds date?
56 Macdonald et al, 5.2.6.b; 3.2.2.ci
57 Ibid,3.2.2a
58 Ibid, 5.2.6
59 White et al, 2.1.1.1.3
60 Ibid,2.1.1.1.2
61 Macdonald et al, 5.2.6.b
62 Ibid,3.2.4
63 Ibid, 6.5.1
64 Fox Snaring. A Code of Practice. BASC. 1994. Snaring foxes: guidance for the snare user. The Game
Conservancy Trust. 1998
65 White et al, 2.1.1.1,2
66 Macdonald et al, 3.2.5
67 Ibid,3.6
68 Ibid,3.6.1.a.iv
69 Ibid,3.6.1.a.i
70 White et al, 2.1.1.2.1
71 Macdonald et al, 5.2.5, White et al, 2.4.2.4
72 Macdonald et al, 5.2.7.b., 7.2.1.a
73 White et al, Section B.1.1
74 Macdonald et al, 3.3.1
75 Ibid,1.1
76 In contrast, there are thought to be some 300,000 wild red deer in Scotland
77 Macdonald et al, 10.2.3
78 Ibid,10.2.4
79 Ibid,2.3
80 White et al,1.2
81 Ibid,1.2
82 Macdonald et al, 5.2.1.a.i
83 White et al,1.2
84 Ibid,1.2
85 Macdonald et al, 2.3.1.a.ii; 2.3.1.c
86 Ibid,2.3.1.c
87 Ibid,1.2
88 White et al, 2.3.1.c
89 Macdonald et al, 2.3.1.b
90 Ibid, 2.3.1.c.i
91 Ibid,2.3.2.b
92 Ibid,2.3.2.b
93 White et al,1.3
94 British Deer Society 1, un-numbered
95 Ibid, un-numbered
96 White et al, 1.3
97 Macdonald et al, 2.3.2.b
98 British Deer Society 1, un-numbered
99 Macdonald et al, 2.3.3
100 Ibid, 2.2.3.a
101 White et al, 1.4.1.a
102 Ibid, 1.4.1.a
103 Macdonald et al, 2.3.4.b
104 White et al,1.5
105 Macdonald et al, 3.3.2.c
106 Ibid, 3.3.2b
107 Ibid,5.4.6
108 White et al, 2.2.2 et al
109 Ibid, 2.2.3
110 Macdonald et al, 5.4.6 et al
111 White et al, 2.2.5
112 Ibid, 2.2.1
113 Ibid, 5.4.6.b
114 Macdonald et al, 2.2.4
115 Ibid, 5.4.6.b
116 White et al,2.2.6
117 White et al, 2.3
118 Macdonald et al, 5.4.5.a
119 Macdonald et al, 5.4.1
120 Ibid, 5.4.3
121 Ibid, 3.2.2
122 Ibid, 5.2.2
123 Macdonald et al, 5.4.1
124 Macdonald et al, 3.3.2.b
125 White et al, 5.4.1
126 Ibid, 3.26
127 Ibid, 3.26
128 Macdonald et al, 7.3.1.a
129 BASC 1, 7.2.1
130 Macdonald et al, 7.3.1.b
131 White et al, 5.4
132 Holnicote Estate Farm Tenants’ Association 1, un-numbered
133 The Exmoor Society 1, 1.14
134 British Deer Society 1, un-numbered
135 BASC 1, 7.1.1
136 Macdonald et al., 7.3.1.b.
137 Ibid, 7.3.1.b.
138 Ibid, 7.3.1.b.
139 Ibid,10.3.1
140 Ibid, 3.4.1a and b
141 Macdonald et al, 10.3.2
142 White et al, 1.1.1
143 Macdonald et al, 10.3.4
144 Ibid, 10.3.4
145 Ibid, 2.4
146 Ibid, 2.4.1.
147 Ibid, 2.4.1
148 Ibid, 2.4.1
149 Ibid, 3.4.2
150 Ibid 3.4.2
151 Ibid, 5.5.4
152 Ibid, 5.5.1
153 AMHB and MBHA 1, 67
154 Macdonald et al, 5.5.3
155 Ibid, 10.4.1
156 Ibid, 10.4.3
157 White et al, 1.2 – 1.4
158 Macdonald et al, 10.4.3
159 Ibid, 10.4.1
160 Ibid, 10.4.4
161 White et al, 1.2
162 Ibid, 1.3
163 Ibid, 1.3
164 Macdonald et al, 2.5.3
165 White et al, 1.4.3
166 Ibid, 1.4.3.1
167Ibid,1.4.3.1
168 Ibid, 1.4.3.1
169 Ibid, 1.4.3.2
170 Macdonald et al, 2.5.3.a
171 Ibid, 2.5.3.a
172 White et al, 1.4.2
173 Ibid, 1.4.1
174 Macdonald et al, 3.5.3
175 Ibid, 5.6.4
176 Ibid, 3.5.3
177 White et al, 2.1.2
178 Ibid, 2.1.2
179 Ibid, 2.1.2
180 Macdonald et al, 3.5.3
181 Ibid, 3.5.3
182 White et al, 2.1.2
183 Macdonald et al, 5.6.2
184 White et al, 2.1.3
185 Ibid,2.2 and 3.2
186 Ibid,2.2
187 Macdonald et al, 5.6.1
188 Ibid, 5.6.4
189 MMHA1,5
190 White et al, 2.1.3 and 5.2
191 Ibid,5.2
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