The Badger Cull - Scientific Q&A

(c) Bertie Gregory / 2020VISION

Q: Is the Government basing the badger cull on scientific evidence? 

A: No scientific conclusions can be drawn from the badger cull pilots.

The Government has undermined the scientific credibility of its own research, by repeatedly changing targets and methods. As a result, no definitive scientific conclusions can be drawn from the pilot culls, as the scientific evidence used to justify them is highly selective. In 2014, Chair of Natural England’s Scientific Advisory Committee, Professor David Macdonald, described the pilot culls as an ‘epic failure’1.

Almost twenty years ago, the Government commissioned a comprehensive study into the spread of bTB through cattle by badgers. The research ran from 1998 – 2006 and remains the most comprehensive scientific study of the effect of badger culling on levels of bovine TB in badgers and cattle in the world. The conclusion of the report was undeniable ‘badger culling can make no meaningful contribution to cattle TB control in Britain’. Lord Krebs, who designed the RBCT, concluded that that “culling is not a viable policy option”. 

The conclusions of the RBCT are available to download, contained within the Final Report of the Independent Scientific Group on Cattle TB - 'Bovine TB: The scientific evidence.'

 

Q: Are badgers the primary cause of bTB outbreaks in cattle?

A: No. Cattle-to-cattle transmission remains the primary cause of outbreaks of bTB in cattle

Whilst roughly 50% of outbreaks of bTB may be related to badgers once subsequent cattle to cattle transmission is taken into account 2, the same study estimated that just 5.7% of outbreaks are caused directly by badgers3. That is, a badger could infect a herd of cattle, but that infection then spreads from animal to animal, so that most cattle catch bTB from other cattle, not from badgers.

 

Q: Has the Badger Cull been successful so far?

A: There is no evidence that rates of bTB breakdowns have been reduced in cull areas.

Badger culling at the licensed sites has produced no measurable change in bovine TB so far4. The recent announcement by Government regarding the improvement of the accuracy of IFNg cattle testing ONLY in areas with at least a year of badger culling will mitigate against attempts to measure the effectiveness of culling itself. Government has so far been measuring success in terms of the numbers of badgers killed. But even here, claims of success are misplaced. For example in 2016 Defra changed the target numbers of badgers to be killed in all seven new culling areas, when some cull companies killed more than double their target easily while others killed barely a half5. 

 

Q: If each cull lasts longer, will the Badger Cull  be more successful?

A: In fact, prolonged culling could actually increase the risk of bTB in cattle

A six-week maximum cull duration was imposed by Defra in 2011 because culls lasting more than this had been found to prompt especially large increases in badger bTB due to the perturbation effect6, 7. However, in 2014 the maximum duration was removed from the license guidelines.

 

Q: Culling badgers must be the only option to control bTB though?

A: Culling badgers is not the only option available to control bTB and help farmers; in fact, it could make it much worse

94% of bovine TB is estimated to come from other herds8. So controlling cattle-to-cattle transmission is likely to have a much bigger impact than controlling badger-to-cattle transmission. Worse still, culling badgers risks making the problem even worse9.

 

Q: Some people say there are too many badgers - do they need controlling?

A: There is no clear link between the density of badgers and rates of bTB in either badgers or cattle.

Badger densities are higher in the cattle-farming areas of western Britain, because the habitat there is most suitable for them. Within this region, however, areas with high badger densities have a lower proportion of infected badgers10.

 

Q: Are badgers a 'pest'?

A: Badgers are a valued species in the UK, protected by law. 25% of the European population is found in the UK, so we have an international responsibility to conserve them. The removal of one animal from the ecosystem has knock-on impacts. For example, large-scale badger culling led also to a doubling of fox numbers.11

Badgers and their setts are protected under the Protection of Badgers Act 199212, which makes it illegal to kill, injure or take badgers or to interfere with a badger sett. Badgers are also protected by the Convention on the Conservation of European Wildlife and Natural Habitats (known as the Bern Convention)13.

 

Q: Is a rollout of the Badger Cull widely supported?

A: The badger cull does not have the support of scientists, the British Veterinary Association (BVA) or the public.

The public do not support it – there are several opinion polls on this. IPSOS/MORI conducted a survey of MPs and found that badger culling was in the top 5 topics on which MPs receive letters from constituents14. It’s not an urban/rural divide either – an opinion poll commissioned by the BBC showed this several years ago, and moreover signatories to the recent e-petition against the expansion of the badger cull by Simon King did not come disproportionally from urban constituencies15. The BVA opposes it on welfare grounds16 and every wildlife charity opposes it.

 

Q: Surely the badger cull is being carried out humanely?

A: Badger culling has been proven to be inhumane.

Continued use of the controlled shooting method has been discredited by the British Veterinary Association as an inhumane practice17. The former Chair of Defra’s Independent Expert Panel, Prof Ranald Munro, has stated publicly that safeguards to badger welfare in cull zones do not reach the standard set by the Animals in Scientific Procedures Act18.

 

Q: Is culling badgers the cheapest method of control of bTB?

A: Culling badgers has been proven to be much more expensive than vaccination.

Between 2012 and 2014, the tax payer spent £16.8 million on the culling of 2,476 badgers19.  This equates to £6785 per badger. Of this figure, more than £4.9 million was spent on policing costs - equivalent to the annual salary costs of more than 120 police officers over a two-year period20. By contrast, vaccination costs £293 per badger.

 

Q: Will vaccinating badgers be as effective as culling?

A: It is vaccination, not culling, that eradicated smallpox and rinderpest, and eliminated rabies from western Europe. Unlike culling, vaccination does not disrupt badger behaviour so it cannot increase TB transmission21  – in fact badger vaccines are highly effective in reducing the transmission from badger to badger. An oral vaccine could be available in the near future.

In 2012, a four-year study conducted by Carter et al., based at The Food and Environment Research Agency (FERA) tested the effects of the Badger BCG vaccine in an area of very high badger densities across 55km² of Gloucestershire. This clinical trial found that the BCG vaccine reduced the risk of vaccinated badgers testing positive to a test of progressed infection by 76%, and reduced the risk of testing positive to any of the available live tests of infection by 54% and conferred protection to non-vaccinated cubs22, 23. A study published in January 2017 found that over a three-year period in three study zones, oral BCG vaccination gave protection to badgers and could be used to reduce incident rates in tuberculosis-infected populations of badgers24.

 

Q: What other options are there? Biosecurity measures on farms are as good as they could be...

A: There are still widely varying measures in place within farms to help reduce the spread of bTB, and biosecurity could be improved

A study of 56 farms in the north-west of England over an area of 100km² found that uptake of biosecurity measures varied widely between farms. It is imperative that more research is done to understand best practice and how farmers could be better supported if preventive measures are to be employed and embraced completely by farmers25.

 

Q: Can conservationists really understand how hard it is for farmers at the moment?

A: We understand that bTB can have a devastating emotional and financial impact on the lives of farmers. We want to work with them to find solutions that work for everyone

The Wildlife Trusts work with over 2,000 farmers every year to help them manage land for wildlife. We own cattle and run several working farms around the country. We understand the impact that bTB can have on farmers and we want to find long-term solutions that work for wildlife and people.

 

References

1Scientific adviser brands badger cull an ‘epic failure’. Article in the Sunday Times 6 July 2014
2 Godfray et al. (2013) A restatement of the natural science evidence base relevant to the control of bovine tuberculosis in Great Britain. Proc R Soc B 280: 20131634. http://dx.doi.org/10.1098/rspb.2013.1634
3 Donnelly and Nouvellet (2013) The Contribution of Badgers to Confirmed Tuberculosis in Cattle in High-Incidence Areas in England. PLoS Currents: Outbreaks, available here: http://currents.plos.org/outbreaks/article/the-contribution-of-badger-to-cattle-tb-incidence-in-high-cattle-incidence-areas/
4 Report of the incidence of bovine tuberculosis in cattle in 2014 - 2015 in the areas of Somerset and Gloucestershire exposed to two years of industry-led badger control, available here: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/574290/tb-badger-control-second-year-analysis.pdf
Summary of badger control monitoring during 2016 - Updating of minimum and maximum numbers during the cull http://www.bovinetb.info/docs/summary-of-badger-control-monitoring-during-2016-updating-of-minimum-and-maximum-numbers-during-the-cull-annex-a2.pdf
Defra (2011) Bovine TB and Badger Control: Consultation on Guidance to Natural England on the implementation and enforcement of a badger control policy – July 2011.
Woodroffe, R., Donnelly, C.A., Jenkins, H.E., Johnston, W.T., Cox, D.R., Bourne, F.J., Cheeseman, C.L., Delahay, R.J., Clifton-Hadley, R.S., Gettinby, G., Gilks, P., Hewinson, R.G., McInerney, J.P. & Morrison, W.I. (2006) Culling and cattle controls influence tuberculosis risk for badgers. Proceedings of the National Academy of Sciences of the United States of America 103: 14713-14717.
8 Donnelly CA, Nouvellet P. (2013). The Contribution of Badgers to Confirmed Tuberculosis in Cattle in High-Incidence Areas in England. PLOS Currents Outbreaks, Edition 1. http://currents.plos.org/outbreaks/article/the-contribution-of-badger-to-cattle-tb-incidence-in-high-cattle-incidence-areas/
9 Woodroffe, R., Donnelly, C.A., Jenkins, H.E., Johnston, W.T., Cox, D.R., Bourne, F.J., Cheeseman, C.L., Delahay, R.J., Clifton-Hadley, R.S., Gettinby, G., Gilks, P., Hewinson, R.G., McInerney, J.P. & Morrison, W.I. (2006) Culling and cattle controls influence tuberculosis risk for badgers. Proceedings of the National Academy of Sciences of the United States of America 103: 14713-14717.
10 Woodroffe, R., Donnelly, C.A., Wei, G., Cox, D.R., Bourne, F.J., Burke, T., Butlin, R.K., Cheeseman, C.L., Gettinby, G., Gilks, P., Hedges, S., Jenkins, H.E., Johnston, W.T., McInerney, J.P., Morrison, W.I. & Pope, L.C. (2009) Social group size affects Mycobacterium bovis infection in European badgers (Meles meles). Journal of Animal Ecology 78: 818-827.
11 Trewby, I.D., Wilson, G.J., Delahay, R.J., Walker, N., Young, R., Davison, J., Cheeseman, C., Robertson, P.A., Gorman, M.L. & McDonald, R.A. (2008) Experimental evidence of competitive release in sympatric carnivores. Biology Letters 4: 170-172.
12 Available here: http://www.legislation.gov.uk/ukpga/1992/51/contents
13 Available here: http://www.coe.int/en/web/bern-convention 
14 Available here: https://www.slideshare.net/IpsosMORI/the-view-from-westminster-ipsos-mori-m-ps-survey-1978-2014
15 Available here: http://www.bbc.co.uk/news/science-environment-13684482
16, 17 British Veterinary Association (2015) BVA calls for change to badger culling method and wider roll-out in England, available here: https://www.bva.co.uk/uploadedFiles/Content/News,_campaigns_and_policies/Policies/Farm_animals/Final%20position%20on%20bTB%20and%20badger%20culling%20AGREED%20at%20Council%2015%20April%202015.pdf
18 Available here: https://www.theguardian.com/environment/2015/sep/02/badger-cull-experts-call-for-immediate-halt-programme 
19, 20 These figures were provided in response to a Freedom Of Information (FOI) request, which is available in full on the Gov.uk website
21 Woodroffe, R., Donnelly, C.A., Ham, C., Jackson, S.Y.B., Moyes, K., Chapman, K., Stratton, N.G. & Cartwright, S.J. (2016) Ranging behaviour of badgers Meles meles L. vaccinated with Bacillus Calmette Guerin. Journal of Applied Ecology http://discovery.ucl.ac.uk/1527401/
22 Carter et al. (2012) BCG Vaccination Reduces Risk of Tuberculosis Infection in Vaccinated Badgers and Unvaccinated Badger Cubs. PLOS One, 7: e49833
23, 24 Gormley et al. (2017) Oral Vaccination of Free-Living Badgers (Meles meles) with Bacille Calmette GueÂrin (BCG) Vaccine Confers Protection against Tuberculosis. PLoS ONE, 12: 1-16
25 Brennan and Christley (2012) Biosecurity on Cattle Farms: A Study in North-West England. PLoS ONE, 7: e28139.