Response to the Public Consultation: Controlling the Spread of BTb in High Incidence Areas in England: Badger Culling

A more up-to-date statement on badgers and bovine tuberculosis is now available and can be found here.

December 2010

The Mammal Society works to protect British mammals, halt the decline of threatened species, and advises on all issues affecting British mammals. We therefore welcome the opportunity to respond specifically to this consultation and to contribute to the process of controlling bovine tuberculosis in cattle.

We recognise that at least some badger populations in the UK are infected with bovine tuberculosis and that badgers may pass the disease to cattle. Here, we respond to the specific issues raised by the consultation documents on badger culling.

Summary of The Mammal Society’s position

•  The Mammal Society believes that policy in animal health and welfare must be evidence-based and properly balanced.
      •    The Mammal Society considers that, on balance, there is insufficient evidence for bTB control policy involving badger culling and sufficient evidence to advise against one.
      •    The Mammal Society considers that there is no scientific basis to support the large-scale, proactive culling of badgers based on cage trapping and shooting.
      •    The Mammal Society believes that the use of piecemeal, reactive, trapping-based control strategies will not reduce the incidence of bTB in cattle and may lead to increases in the disease.
      •    The Mammal Society believes that implementing multiple policies to control bTB in cattle in the same place at the same time will not allow conclusions to be drawn on the effectiveness of any single policy. At worst, badger culling may increase bTB incidence in cattle, thus undermining any positive effects contributed by cattle-based policies.
      •    The Mammal Society is opposed to the transfer of responsibility for badger culling to farmers and landowners.
      •    The Mammal Society is opposed to the gassing and snaring of badgers on animal welfare grounds and considers that there is currently no scientific evidence to support their introduction within the UK.
      •    The Mammal Society is extremely concerned that several of the policy options being considered by Defra are those that have been rejected previously on scientific and/or animal welfare grounds.

Question 1. In light of the evidence presented as part of this consultation, on balance, do you think a policy to cull badgers should be part of the approach to help control the disease in cattle in high incidence areas?

•  On balance. No. Culling of wildlife reservoirs of livestock diseases, as well as of infected livestock has proved an effective strategy to eradicate or reduce the prevalence of some diseases, including bovine tuberculosis (bTB), in some countries (Krebs 1997). However, in the case of bovine tuberculosis in the UK, with the badger implicated as the main wildlife reservoir of the disease for cattle, we conclude that, currently, the scientific evidence does not support a policy to cull badgers to help control the disease in cattle in high incidence areas. Our reasons are as follows:
•  In his report commissioned by MAFF on badgers and bTB, Krebs (1997) concluded that previous attempts to control bTB by culling badgers had not resulted in a significant impact upon the incidence of the disease in cattle. We concur with this view. Here, we consider only evidence on this issue arising since 1997.
•  A major assumption underpinning a badger culling policy is of a positive association between badger abundance and disease incidence and prevalence within the badger population. The only study to investigate this has refuted the existence of such a relationship (Rogers et al. 1999). No empirical studies support the notion that reducing the badger population will reduce the incidence or prevalence of bTB within the population.
•  It has been suggested that culling badgers to reduce the incidence of bTB within their populations constitutes a significant animal welfare objective. This suggestion has no scientific basis and is philosophically flawed. Whether humans should interfere with disease in wildlife populations for the benefit of individual animals is an emotive and unresolved debate. However, it has been estimated that bTB is responsible for only 7% of badger mortality (Rogers et al. 1999); in the same area and over the same time only 0.5% to 5% of badgers were infected with Mycobacterium bovis, the causative agent of bTB. It is true that badgers at advanced stages of infection suffered a higher mortality rate but these represented only a very small fraction (0.6%) of the total population (Wilkinson et al. 1999).
•  Further, as stated above, since no simple linear relationship exists between bTB incidence or prevalence in badgers and their abundance (Rogers et al. 1999), culling badgers cannot be expected to reliably reduce the number or proportion of badgers suffering from bTB. To the contrary, since the vast majority (> 80%) of badgers culled are likely to be free of the disease and in view of some of the methods included within this consultation (especially snaring and gassing), culling itself would be far more deleterious to badger welfare.
•  The culling trial in East Offaly, Republic of Ireland (O Mairtin et al. 1998; Eves 1999), identified a decrease in bTB incidence in cattle over time, but the lack of replication and the low level of localised culling in the ‘control’ areas reduced the scientific rigour of this study; interpretation of the results is consequently problematical.
•  The Four Areas Project (FAP) to investigate the impacts of badger culling on bTB in cattle, conducted across Ireland between 1997 and 2002, was replicated, but lacked true controls (Griffin et al. 2005). The study reported a significant difference in bTB incidence in cattle between areas where badgers were intensively culled and those where a low-level of culling was exercised under a reactive strategy. The latter may have increased the incidence of bTB in cattle within these areas (Donnelly et al. 2003), so it was not possible to compare these results empirically with a policy of no culling. Furthermore, differences between apparent badger densities and social structure in TB hotspots of Ireland and England and differences in the approach and culling methods used within the FAP limit the applicability of these results to the situation in England.
•  The Randomised Badger Culling Trial (RBCT) in England indicated that localised, reactive culling in response to cattle herd breakdowns with bTB did not reduce the incidence of bTB among cattle herds, but may even have exacerbated the problem (Donnelly et al. 2003). However, some areas were recruited to the trial with insufficient time for the epidemiological effects of culling to become manifest, making interpretation of the high level of consistency between replicates difficult.
•  One suggested explanation of this result was that perturbation of badger social groups caused badgers to move more, and so increased contact rates with cattle, thus increasing the rate of transmission from badgers to cattle (Donnelly et al. 2003). Recent evidence from the RBCT supported the idea of badger social perturbation, by demonstrating that badger territory size was significantly and consistently larger in areas experiencing culling than in areas not experiencing culling; there was also an increase in territory size in non-culling areas immediately adjoining culling areas (Woodroffe et al. 2005).
•  Furthermore, despite a significant and consistent decrease in bTB incidence in cattle within proactively culled areas (in comparison to non-culled areas), the area up to 2km outside of the culling area experienced a significant increase in cattle bTB incidence (in comparison with the area 2km around non-culled areas) (Donnelly et al. 2005). However, this effect was not significant if measured from the first follow-up cull, probably due to more complete removal of badgers from the areas (Donnelly et al. 2005).
•  During the FAP, every attempt was made to reduce the likelihood of immigration at the edge of each trial area, which might otherwise have resulted in a perturbation effect at the edge of trial areas, by bounding each with for example, major rivers or the coast (Griffin et al. 2005). Furthermore, culling was very intensive, with snaring exercises undertaken three times per year and with lactating sows being culled. These strategies undoubtedly increased the likelihood of near-complete badger removal. No analyses were undertaken to assess the possibility of a perturbation effect, possibly because the incidence of bTB in cattle was so markedly reduced in comparison to reference areas. However, disruption of badger social organization was invoked as an explanation of cases of different bTB isolates being found in badgers after culling had taken place and the authors conceded that culling activity may have precipitated badger movement between setts (Olea-Popelka et al. 2005).
•  Given the limitations of both the Irish FAP and English RBCT, and cautiously inferring from both, it seems plausible to hypothesise that large-scale badger culling, with reduction of badger populations to extremely low levels and in areas where immigration can be discounted, would contribute to a reduction in the incidence of bTB in cattle. However, this hypothesis has not yet been tested with satisfactory scientific rigour within England or elsewhere and there remain considerable uncertainties concerning the ability to achieve a substantial level of badger removal. It therefore cannot justifiably be implemented as policy. Furthermore, the scale and intensity of culling required to achieve the main objective has not been assessed, let alone specified. Local extermination of badger populations might be a likely outcome. This is certainly likely to be unacceptable to the British public (White & Whiting 2000) and contrary to the Bern Convention. Except under exceptional circumstances (for example rabies control), and where such a policy is robustly demonstrated to be likely to provide a significant benefit, The Mammal Society opposes any policy that risks local extinction of any native mammal.

Question 2. Comments are invited on the options considered and the costs and assumptions made in the Partial Regulatory Impact Assessment.

•  The Mammal Society questions the presumptious use of the term ‘balanced’ in the title of the impact assessment and elsewhere. Introducing badger management to provide balance would necessitate a clear benefit to derive from culling. We contend that, at best, such benefits are currently equivocal, as discussed above.
•  At paragraph 20 it is stated that lethal removal is the only way to reduce the number of infectious badgers. While this seems a plausible conclusion, social perturbation and consequent increased contact between badgers (Cheeseman et al. 1993; Roper & Lups 1993; O’Corry-Crowe et al. 1996; Tuyttens et al., 2000; Woodroffe et al. 2005) means that lethal removal will probably only reduce the incidence of bTB in badgers after the badger population has been reduced beyond some un-quantified threshold. This does not equate to the same thing. Statements made on the first premise seem prejudicial.
•  As well as the factors listed at paragraph 22, The Mammal Society contends that a decision to cull badgers should first and foremost be based upon evidence regarding the likelihood of culling reducing the incidence of bTB in cattle.
•  With reference to paragraphs 23 and 24, we agree that logistical difficulties arising from undertaking such a large-scale field trial (e.g. non-compliance of landowners, variable dates of cull implementation, interference by saboteurs) have made interpretation of results arising from the RBCT problematic. Moreover, similar criticisms can also be levelled at the Irish FAP. The RBCT receives a great deal of criticism in the consultation documents; a balanced approach would have dealt equally critically with other relevant evidence. It is unfortunate that this did not happen. This apparent bias also appears in paragraph 25 where the results of the RBCT are interpreted beyond their capability.
•  No evidence regarding the effects of varying culling efficiency were presented in Donnelly et al. (2005) and estimates of culling efficiency with limited variability cannot be used to support the policy of widespread, draconian culling. Furthermore, throughout the consultation documents the potential problems associated with culling (especially the effects of social perturbation, but also non-compliance of landowners and interference by saboteurs, for example) seem to be treated with suspicion and all but disregarded.
•  The Mammal Society agrees that 10 years is a suitable period over which to evaluate costs due to the possibilities and uncertainties outlined within the impact assessment document. However, we feel it is unacceptable to assume that benefits accrue over 10 years when strategies have been implemented for at most only 5 years. There is no evidence to support this assumption.
•  We note that the RBCT has not yet been able to demonstrate what effect recovery of badger populations will have upon the incidence of bTB in cattle, but simulation models have illustrated that this is likely to be a fundamental problem of finite culling (Smith et al. 2001a,b).
•  We are concerned that no assessment of the value of badger culling to scientific groups, wildlife organisations (other than badger welfare groups) and wider society has been taken into account. We also contend that the values that these groups attribute to badger culling may not be linearly associated with badger density or the magnitude of the cull. Furthermore, the relative values of different methods of culling, in terms of badger welfare, do not appear to have been taken into account.
  We believe that these are important considerations for a policy that will impact widely upon society while the majority of benefits will accrue to a minority.

Options & Discussion

1. A) No badger management (at least pending the outcome of the RBCT)

Given the uncertainty regarding the net benefits of badger culling, this presents, to The Mammal Society, the most justifiable option until the final results of the RBCT are fully analysed, interpreted, peer-reviewed and debated.

The expectation that this policy would result in no change to the increasing trend in cattle herd breakdowns is unrealistic since other, non-badger-based, policies are also proposed, such as pre-movement testing. These alone should reduce the incidence of bTB in cattle (Gilbert et al. 2005; Johnston et al. 2005), as they have in Northern Ireland since early 2003 (Hansard 2005). Badger culling, at the same time as implementing such measures, will make their benefits impossible to assess. The Mammal Society suggests that the likely reduction in cattle bTB incidence due to other policies should be included within the analysis and the additional effects of badger culling, both positive and negative, assessed alongside this to provide a properly balanced perspective.

The statement that no economic benefits were identified from the analysis of the ‘no culling’ option is seriously misleading. This analysis used that option as the baseline for comparison with other options. If the analysis was re-done, with another policy option as the baseline, this option would yield a net value.

While an increase in illegal culling, possibly using inhumane methods, may seem a plausible consequence of this option, there is no evidence to support this hypothesis. On the contrary, evidence from the RBCT suggested that illegal culling was not widespread in survey-only areas (Woodroffe et al. 2005). There is no reason to assume that law-abiding farmers whose licence application is rejected will turn to illegal culling, nor that those unlawfully killing badgers now will apply for licences should that option become available.

1. B) State Controlled Cull

Should the Government decide to implement a cull of badgers to control bTB, The Mammal Society is of the view that a state-controlled cull would be the only acceptable option. It would be the most controllable and most co-ordinated culling mechanism, although we maintain that it is unlikely to achieve a net reduction in bTB incidence in cattle. It would also be the most likely to present opportunities for carcass collection and monitoring, which we consider essential, whilst being most under scrutiny and with an emphasis placed upon animal welfare. This view is in general agreement with the environmental benefits stated for this option.

i) RBCT proactive cull methodology: trapping and shooting with a handgun.
Given the requirement to maintain culled areas at low badger densities to reduce the effects of badger social perturbation on cattle within culled areas, it is unlikely that culling an area twice will achieve this objective for periods in excess of 5 years. Assessing the costs and benefits of culling repeated more than twice, over the 10-year period would constitute consideration of a more appropriate strategy.

ii) Restraints method (based on RoI four areas trial methodology), snaring and shooting.
The Mammal Society notes that while snares used in the Republic of Ireland are considered more effective at badger removal, no empirical studies have been undertaken to qualify or quantify this. Further, we note that the Irish Department of Agriculture and Food are considering supplementary methods of badger capture in addition to snares, since they perceive that the ability of snares to catch cubs was very poor. Therefore, it might be more appropriate to assess the benefits and costs of a strategy combining the use of snares and cage traps. We look forward to seeing the re-worked analysis with the welfare value of snares and cage traps properly compared.

iii) RBCT proactive cull methodology using sett based control. Gassing.
No assessment has been made of this technique, no trials have been undertaken, and this is at present a purely notional proposition. It needs proper evaluation before it can be the subject of a robust comparative analysis and/or a consultation.
 
C) Licensing groups of farmers to cull under the Protection of Badgers Act 1992.

Imposing no charge for a licence risks attracting a large number of applications. Given that farmers who are truly negatively impacted by badgers’ presence are likely to experience serious financial impacts already, perhaps only a nominal fee should be charged (to cover administration costs). It is important to reach a firm conclusion on whether this is appropriate or not since this cost, coming early in the exercise, is likely to impact quite significantly on the net result. The Mammal Society would not oppose the inclusion of a nominal licence fee in order to dissuade a large number of applications, although we do not support a farmer-led cull (see below).

The assumption that highly efficient culling over small areas would avoid edge effects is clearly unfounded and no information exists to support it. Indeed, interpreting the results of the proactive part of the RBCT (Donnelly et al. 2005), it seems fair to conclude that any level of culling is likely to result in a perturbation effect outside of the culling area. This should be costed into the analysis. It is also important to consider what would be done for farms that suffer an increased risk of bTB on the edge of a culled area.

The qualifying criterion of 75% of land under compliance is arbitrary. Presumably this is based on an approximate average of 75% of land under compliance during the RBCT, which was a scientific trial and did not represent policy implementation. We note that compliance ranged from 55% to 95% between Trial areas (ISG 2004), and we are unaware of any evidence suggesting that 75% compliance is necessary to achieve a reduction in bTB incidence in cattle. As a consequence of non-compliance, even if all land under compliance within the culling area experienced 100% effective culling, which is highly unlikely, badgers would remain in the area and would be expected to alter their movement patterns, so resulting in a perturbation effect. This should be costed into the analysis.

The deterministic assumptions that farmers will survey in year 1 and cull 3 times per year for 5 years are unrealistic. The farmer-input variable should be stochastic, with a wide distribution to reflect the likely high variability in farmer effort.

 No consideration appears to have been given to farmers’ opportunity costs. Given that many farmers have insufficient time to implement basic biosecurity procedures to protect their herds from contact with badgers (Bennett and Cooke 2005) it is likely that investing time in badger culling would have a considerable opportunity cost, which should be included within the analysis.
The statement that this option is not “reactive culling” is correct, insofar as it does not represent culling in response to a single herd breakdown of unspecified cause and insofar as repeated culling is proposed. However, it cannot be assumed that badger social perturbation will not occur under this option: even badger eradication within a core area is likely to impact upon badgers, and consequently cattle, outside the area (Woodroffe et al. 2005; Donnelly et al. 2005).

Further, as stated above, the efficiency of farmers in removing badgers from an area cannot be assumed to be 100% and must be considered variable. This should be factored into the analysis. As it stands, the large number of assumptions used underestimate the variability inherent in likely farmer inputs and highlight the high degree of uncertainty associated with these inputs. Therefore, The Mammal Society has little confidence in the results of this part of the analysis, nor in the subsequent conclusions of the study in comparison to that for the other options, which relied more heavily, but still incompletely upon empirical evidence.

We disagree that this option represents a less targeted approach than other options, since there is no way of confidently attributing a herd breakdown to badgers (as opposed to ruling out other factors, which would also be a flawed approach). No approach can be strictly targeted with reference to the objective of reducing badger to cattle transmission. However, we agree that the potentially lower participation rates under this option would probably further reduce the likelihood that a badger cull yields net benefits.

Low uptake is only likely to increase any edge effects if those properties lie on the edge of the culling area. If they lie in the interior, they will probably contribute to badger social perturbation within the core area and further hamper efforts to control bTB in cattle by culling badgers.
With small-scale, localised culling, any perturbation effect in the area peripheral to the culling area is likely to be proportionately much greater than for large-scale culling, and immigration into (recolonisation of) the core area is likely to be much quicker. Noting our comments above, The Mammal Society contends that the scientific evidence suggests that small-scale local culling is highly unlikely to yield net benefits.



Analysis of Costs and Benefits

The analysis assumes that half of all confirmed TB incidents arise from badger-to-cattle transmission. The Mammal Society contends that this assumption has no scientific basis. Whatever values are used must be varied under several scenarios to reflect a number of possible outcomes, given the number of possible inputs. Further, the assumption that badger-to-cattle transmission can be reduced in direct proportion to the reduction in badger population is false, as has been known for some time. The concept that badger social perturbation is a potential consequence of badger culling has been accepted for over 10 years (Cheeseman et al. 1993; Roper & Lups 1993; O’Corry-Crowe et al. 1996; Tuyttens et al., 2000).
The results of the RBCT support this and suggest that social perturbation can undermine the benefits of culling (Woodroffe et al. 2005, Donnelly et al. 2005). Hence, a linear relationship between badger density and contact with cattle cannot be assumed. In addition, the incidence of bTB in badgers is unlikely to vary linearly with abundance (Rogers et al. 1999), so the infective force, notwithstanding perturbation, is unlikely to vary in proportion to the reduction in badger population. This scant regard for the ecological component of epidemiology undermines the outputs of the analysis.

The assumption that the benefits of a 5-year cull will accrue over 10 years is unfounded. There is no evidence from the RBCT to demonstrate this and, on the contrary, simulation models suggest that badger populations are likely to recover quickly (Smith et al. 2001 a, b). Social perturbation and naïve immigrant badgers encountering residual infection within the environment may in fact increase the incidence of bTB in both badgers and cattle. While it is true that this has yet to be demonstrated empirically, the possibility cannot be ignored in these proposals for action.



Enforcement, sanctions and monitoring

We note that the costs of wider monitoring of badger populations were not included within the analysis. This exercise is likely to be costly and, as is the nature of monitoring exercises, will require regular repetition over time and space. The Mammal Society contends that these costs, while remaining constant between policy options, should be included within the analysis in order to inform policy makers whether and what magnitude of benefits any policy option could be expected to yield.
Consideration of what sanctions will/can be invoked if a licensee or group of licensees fails to cull a sufficient number of badgers is unjustified. Estimation of badger abundance is notoriously difficult and fraught with uncertainty (Wilson et al. 2003). In addition, immigration from both culled and un-culled social groups is likely to replenish culled social groups. Consequently, it will not be possible for an absolute target cull to be set. This further hampers regulation and hence implementation of a farmer-based cull.



Comments on options within the consultation document:

1. A) Individual licensing to cull badgers to help control bovine TB

There is no evidence to suggest that such an approach would help control bovine TB. On the contrary, this approach might produce results similar to those of the reactive strategy undertaken as part of the RBCT (Donnelly et al. 2003), which has been demonstrated to produce no benefit and possibly a detrimental effect. Furthermore, it may pose considerable animal welfare problems, would be difficult to co-ordinate, and would be impossible to police.
The Mammal Society does not support the issuing of licences to cull badgers to control bTB in cattle.

1. B) General cull

This approach appears most similar to the proactive component of the RBCT, which demonstrated a significant reduction in the incidence of cattle herd breakdowns in the core of proactively-culled areas but an increase in incidence in neighbouring areas. The intent to bound such areas would presumably be to prevent such edge-effects. Only substantial physical geographic features (the sea, mountain ranges) would be likely to achieve this (Donnelly et al. 2005). County boundaries mostly do not present a suitable physical barrier to social perturbation effects. However, we also note that social perturbation within culled areas may have been responsible for the declining beneficial effect on cattle herd breakdowns that occurred as a function of increasing distance from the centre of proactively culled areas (Donnelly et al. 2005).

Highly effective methods of badger removal, or at least, methods that can remove more badgers than in the RBCT, low levels of non-compliance by landowners within areas to be culled and physical boundaries on all sides of the cull area may be required to reduce badger abundance sufficiently to return a net benefit; moreover, culls would need to be repeated regularly to maintain such an effect (Woodroffe et al. 2005). Such a widespread and draconian culling policy would have implications for badger conservation and the Government’s ratification of the Bern Convention. The Mammal Society would not support any policy that risks eradicating a native species from substantial parts of its natural range, other than under exceptional circumstances.

In the absence of evidence that such a policy would be effective for bTB, the Society does not support a general cull.
 
C) Targetted cull
This option appears similar to the reactive cull of the RBCT. Given the consistency of results amongst reactive trial areas, it seems reasonable to conclude that similar results should be expected should this option be implemented as policy. No benefit and a risk of exacerbating the problem could be expected (Donnelly et al. 2003).
The Mammal Society does not support this option.

Question 3. Under what circumstances should the Government grant licences to cull badgers for the purpose of preventing the spread of bovine TB under the Protection of Badgers Act 1992?

Until scientific evidence demonstrates that badger culling can prevent the increase in incidence and spread of bovine TB within badgers and cattle, The Mammal Society would not support the use of the Protection of Badgers Act 1992 or any other legislation to grant licences to cull badgers for this purpose. Scientific evidence suggests that culling badgers may promote the spread of disease within the badger population and may result in increased cattle herd breakdown rates (Donnelly et al. 2003; Donnelly et al. 2005; Woodroffe et al. 2005). We regard this as sufficient evidence to deny applications to cull badgers under the Act.

Question 4. What qualifying geographic criteria would be appropriate, achievable and reasonably likely to be an effective disease control measure?

Noting the caveat that The Mammal Society does not support the culling of badgers to control bTB in cattle, only substantial physical barriers would prevent perturbation of badger social groups peripheral to culling areas from deleteriously affecting herds within culling areas. Such features are likely to be restricted to coasts and mountain ranges but there is no empirical evidence to support this. The independent auditor of badger surveying procedures used during the RBCT noted that the ability of different topographic features to limit badger movement had not been assessed and required quantification. The Independent Scientific Group on bTB concurred (MAFF 2001). However, we note that, anecdotally, badgers have been observed regularly crossing major motorways and rivers, so it is unlikely that these will constitute a sufficient barrier. It would also be necessary to delineate culling areas on all sides by adequate features to be effective. We consider it highly unlikely that sufficient bTB hotspots are bordered on all sides by such features, further making the aims of this strategy un-achievable.

Question 5. How could farmers ensure sufficient coverage to deliver a sustained cull over a large area?

Should the Government decide to license farmers to cull badgers in an effort to control bTB, it would be necessary to cover a sufficiently large area, bounded by substantial geographic features. This would require co-ordination amongst farmers and landowners. Comparisons could be drawn with the efforts of rabbit clearance societies, deer management groups and co-ordinated fox control in Australia, so lessons could usefully be learnt from these.

For example, while the efforts of some deer management groups (which largely appear composed of enthusiasts) appear to be able to maintain abundances of deer within tolerable levels (Manning 2005), not enough groups have yet been set up to stop the spread and growth of wild deer populations at the national level (Ward 2005). In New South Wales, Australia, a campaign to control foxes successfully raised awareness of the problems caused by foxes and raised a high level of participation amongst farmers. However, it was not very successful at reducing production losses caused by foxes or at suppressing local fox populations (Gentle 2005). The inability of farmer groups to self-co-ordinate contributed significantly to this failure. These examples and the experience of the RBCT suggest that full compliance by all landowners within an area to be culled is extremely unlikely.
This will render farmer-led landscape-scale attempts to cull badgers to control bTB in cattle unworkable.
There is no indication, within the consultation documents, that farmers would be willing to undertake such a large-scale and repeated exercise. On the contrary, a survey of farmers recently experiencing a herd breakdown indicated that only approximately 40% to 50% of respondents favoured badger culling at all (Bennett and Cooke 2005). Furthermore, during the RBCT, full compliance was achieved over approximately 55% to 95% of land with 5% to45% of land non-compliant (ISG 2004). If these data are indicative of attitudes amongst farmers, it appears unlikely that farmer-led culling could achieve sufficient compliance.

Question 6. What qualifying disease history would be appropriate?

This question assumes a causal link between badgers on a property and a history of bTB within the herd. Given knowledge of the poor sensitivity of the comparative intradermal tuberculin test in cattle (Francis et al. 2001), and knowledge that a significant proportion of persistent herd breakdowns are due to cattle-based factors (Gilbert et al. 2005; Johnston et al. 2005), herd disease history can only be considered an ambiguous and arbitrary variable on which to base the decision to cull badgers. The Mammal Society does not believe that there is an appropriate qualifying disease history to justify a badger cull. More appropriate, yet still flawed, qualifying criteria might require an epidemiological survey, such as TB99, carried out by trainedprofessionals to rule out cattle-based factors in addition to a field survey to identify the presence of badgers on the premises.
However, we note that it is possible that the presence of a cluster of infection within a badger population could be the result of transmission of the disease from cattle to badgers or vice versa (Woodroffe et al. 2005b).

Question 7. What could be included in the criteria to define those farmers eligible for a licence to cull badgers?

Until it has been demonstrated that reactive culling can have a net beneficial impact on the incidence of bTB within cattle The Mammal Society cannot support such a policy. The criteria within the consultation document specific to this question mirror some aspects of the reactive component of the RBCT, except that the trigger for culling would be different (which is immaterial) and culling is proposed to be repeated (which is probably important, but yet to be evaluated). In addition, the concomitant imposition of biosecurity measures, use of improved diagnostics and pre-movement cattle testing would make it impossible to deduce which measures had caused any reduction in incidence should one occur. Further, the suggested values of 1 to 3km from the boundary, 5 years of culling and 75% of land under compliance are completely arbitrary with no reasonable basis in science or other valid source of support.
This could lead to a meaningless, counterproductive and invalid policy, completely contrary to the Government’s desire for evidence-based policy.

Question 8. Would it be practical for primary herd owners to recruit neighbours and adjoining landowners to achieve, say 75% coverage within 1km of the boundaries of their holding? If not, what might be achievable and reasonable?

The Mammal Society is not in a position to say whether this is practically possible since answers to this question can only be conjectural. However, if only approximately 40% to 50% of farmers favour badger culling (Bennett and Cooke 2005), it seems likely that attempts by pro-culling farmers to recruit neighbours would lead to disputes within the farming community. In addition, other major landowners, such as the National Trust, Woodland Trust, the Wildlife Trusts and the Forestry Commission may have their own views on badger culling to control bTB in cattle and these may not converge with the views of neighbouring farmers. More generally, we consider the criteria of 75% compliance of land and 1km from the holding’s boundary to be arbitrary and unsubstantiated (see comments on the partial regulatory impact assessment, above).
Unless evidence can be produced to support the use of these criteria to promote achievement of the main objective (a reduction in bTB incidence in cattle), it is difficult to see why they have been set and impossible to judge whether they can be considered reasonable or otherwise.

Question 9. Over what size of area could self co-ordinated groups of farmers and landowners be expected to manage a cull consistently and efficiently for up to 5 years, with a high degree of coverage?

Answer as above. In addition, badger social perturbation seems to occur at every scale of culling and irrespective of culling efficiency (Cheeseman et al. 1993; Roper & Lups 1993; O’Corry-Crowe et al. 1996; Tuyttens et al. 1999; Tuyttens et al. 2000). However, considered together, the results of the reactive and proactive components of the RBCT (Donnelly et al. 2003, Donnelly et al. 2005) appear to imply that the effects of badger social perturbation on cattle vary according to the severity and distribution of culling within and around each social group. We agree that culling over small areas is unlikely to deliver the benefits intended by the policy, but results presented by Donnelly et al. (2005) suggest that the same is true for culling over extremely large areas. We suggest that, while possible, the notion that areas may coalesce to spread the benefits of culling widely, presumably due to increasingly widespread issuing of licences to cull, is an un-tested hypothesis, which would more appropriately be addressed by scientific investigation than by policy implementation. It would be more plausible to hypothesise that a high level of licensed culling within a large target area could at best result in a situation comparable to the proactive component of the RBCT; effectively, no net benefit (Donnelly et al. 2005).

The Mammal Society does not support a policy of self co-ordinated groups of farmers and landowners managing culling at any scale.

Question 10. Are there other methods of culling which should be considered?

Where culling of wild mammals is deemed necessary The Mammal Society does not oppose the use of methods demonstrated to be humane. Given that some of the methods listed (specifically gassing) have been concluded to be inhumane from previous trials, we would not wish for other inhumane methods to be considered in addition.

Question 11. Is gassing appropriate for use under licence by groups of farmers, landowners and their agents?

Gassing of badger setts with hydrogen cyanide was the main method of culling used during earlier attempts to control bTB in cattle (Krebs 1997). Trials to investigate the likely effectiveness of hydrogen cyanide to kill all badgers within a sett discovered that the gas did not reach all chambers and passages within a sett at sufficient concentrations to present a lethal dose. It was therefore concluded to be an inhumane method of control (Zuckerman 1980). Despite research being underway to determine the effectiveness and humaneness of carbon monoxide as a gas for culling badgers, until this research is accepted as effective and humane by peer review The Mammal Society cannot accept that gassing is an appropriate method of culling badgers.

Question 12. Would there be a need for training of licensees? If so, what form should this take?

Should the Government decide to licence private persons/firms to gas badger setts, The Mammal Society believes that training should be mandatory, prior to the granting of such a licence, to ensure acceptable standards of welfare. Such training would be equally necessary if DEFRA staff are to be used.
In either case, independent validation of the training would be necessary.
 

Question 13. How could this training be provided?

In the present state of knowledge (total ignorance) appropriate training cannot be provided. There is no publicly available evidence on gasses to be used, concentrations, time to death, LD50, humanity or any other necessary criteria. Presumably Veterinary Colleges or Agricultural Colleges could supply the appropriate courses, if or when they have the information on which to base them.

It is not clear how these should be funded.

Question 14. Would the shooting of free running badgers (under licence) be practical and acceptable?

For the shooting of badgers, the Protection of Badgers Act 1992 specifies shotguns of not less than 20 bore and rifles producing 160ft.lbs of muzzle energy and using a bullet weight not less than 38 grains.

This is presumably based on an assessment of the relative welfare benefits of different weapons, but The Mammal Society is unaware of research undertaken to support this and we would require such research before passing comment on the suitability of shotguns and centre-fire rifles to kill badgers humanely. Should the Government decide to licence members of the public to shoot free-running badgers it would be necessary to draw-up guidance on best practice and ensure training is provided to increase the likelihood of good practice in the field. This is the route through which the shooting of wild deer has become a generally humane practice.

However, since only a proportion of badgers are likely to be observable at any given time, the removal of a few animals by shooting will probably result in social perturbation and consequently may increase the problem of the transmission of bTB from badgers to cattle (Cheeseman et al. 1993; Roper & Lups 1993; O’Corry-Crowe et al. 1996; Tuyttens et al., 2000; Woodroffe et al. 2005). The Mammal Society does not support the shooting of free-running badgers as a practical means of controlling bTB in cattle.

Question 15. What features should be included in the design and use of the body snare? Are there particular features which should be avoided or included?

The Mammal Society does not promote the use of snares and does not provide specialist advice on their design or construction. Snares were not considered an acceptable tool for badger capture during previous culling policies and no evidence has been presented to change this position. However, we feel that should the Government decide to use snares to capture badgers, features should include: heavy gauge wire to avoid cutting the skin and reduce the likelihood of damage to blood vessels and a free-running mechanism to prevent constriction and strangulation.
Features to be avoided include: fine gauge wire, a self-locking mechanism or any mechanism that prevents the free-running of the wire along itself. Any pattern for snares should at least be tested in accordance with and conform to standards laid out in the Humane Trapping Standards Directive.

Question 16. What inspection intervals for checking snares would meet welfare considerations and be practical?

The longer an animal is held in a snare, the greater will be the risk of distress and injury. Therefore there will inevitably be a trade off between welfare and the practical constraints of using snares. Very careful consideration would need to be given to this, and it should be borne in mind that the use of snares by farmers would be difficult, if not impossible, to police effectively. The potential for serious welfare problems to arise using snares as a method of capture, no matter how well perfected the snare design and protocol might be, is high. The possibilities of misuse and accident (e.g. to pets) are also high.
For these reasons, The Mammal Society does not consider snaring a viable option for culling badgers.

Question 17. What skills and competencies for culling are required to ensure body snares are safely and effectively deployed?

The Mammal Society does not consider use of snares to be appropriate, does not consider that members of the general public should be licensed to snare badgers, and the question is therefore inappropriate.

Question 18. Is there a need for training for farmers or licensees? If so, what form should this take?

The Mammal Society does not consider use of snares to be appropriate, does not consider that members of the general public should be licensed to snare badgers, and the question is therefore inappropriate.



Question 19. How could this training be best provided?

The Mammal Society does not consider use of snares to be appropriate, does not consider that members of the general public should be licensed to snare badgers, and the question is therefore inappropriate.

Question 20. What methods of disposal would be suitable to minimise risk of disease transmission, assist in monitoring a cull of badgers and be practical?

Collection of material from culled badgers would be essential to monitor the cull, to assess impacts on badger populations and to monitor their disease status. This would require co-ordinated collection of carcasses. We further contend that in addition it would be necessary for licensees to report on the number of setts targeted and the number of badgers killed and/or retrieved after a cull. This would importantly inform the scale, potential impact and potential effectiveness of culls.

Since carcasses arising from any culling policy will be the result of efforts to control bTB in cattle, the Animal By-Products Order 1999 states that they should be disposed of accordingly. Incineration is the preferred method, but rendering may also be an option. Burning other than by incineration and burying are also seen as acceptable methods of disposal where access to the place is difficult or if the volume of material does not justify transportation. Under these circumstances, and should the carcasses not be required for monitoring purposes (which we would strongly recommend for as many carcasses as possible) The Mammal Society considers burning to be preferable to burial. Mycobacterium bovis, the bacterium that causes bTB, can persist for long periods of time when protected from sunlight and desiccation (King 1997) such as might occur when it is buried underground. Burial also risks contamination of water courses. The Mammal Society does not consider burial a satisfactory method of carcass disposal.



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