A new article in Vet Times reports on the Torgerson et al (2025) paper published in Royal Society Open Science last month, that has prompted calls to stop all badger culling immediately. The badger culling policy has, it says, relied on a ‘basic statistical oversight’.
The article picks up on comments by the new paper’s reviewer, Biomathematics and Statistics Scotland director Mark Brewer, who argued that “in such a contentious area as this, it is naive to imagine that a single analysis by a particular group of scientists should be seen as sufficient”.
In a noticeable first and potential change of direction, the article quotes Chief Veterinary Officer Christine Middlemiss as saying that Defra is “really looking to protect our key species through vaccination and progress that with badgers, as a key wildlife species, but cattle as well.”
The peer-reviewer of the new scientific paper, Torgerson et al 2025, published on June 11th is the Director of Biomathematics and Statistics Scotland (BIOSS). The paper is concerned with analysis of the Ranomised Badger Culling Trial (RBCT). Below, you can see the text of the review together with the authors responses, as addressed to the editor. Also highlighted (bold italics) are a few points that seem particularly important & difficult to disagree with, even if you don’t understand statistics. It should be noted that the two reviewers of the Mills et al. (2024) papers that Torgerson et al. is rebutting, declined to submit a review of the new Torgerson paper. In other words, they praised the two Mills et al papers, recommended them for acceptance, but declined the opportunity to defend their decision by explaining their thinking on Torgerson et al (2024 & 2025). They remain anonymous, which is interesting from an integrity perspective.
Torgerson: The reviewer has made a number of comments. We have addressed these where necessary and made some amendments to the text. We would also like to thank the reviewer for these helpful comments which we hope have improved our manuscript.
Reviewer: Comment. Overall it seems there is strong disagreement over competing data analyses on what is already a highly contentious issue, which has significant implications in terms of ecology and agriculture. I have been asked to comment on one small part of the ongoing discussion, which I will do – however, my overall, strongest recommendation is that, given the importance of the underlying issue (both scientifically and politically) that a proper investigation be conducted to establish an agreed position involving all parties. A continuing to-and-fro among different sets of authors – each, I am sure, well-meaning in their own ways – serves little purpose, and there are better, more efficient and effective ways of resolving disagreements than in the pages of an academic journal.
Torgerson: The underlying issue (mass culling of largely healthy badgers across much of England and in Ireland) is the result of the original analysis by Donnelly et al, first published in Nature in 2006 and papers derived from that, and subsequent analyses. Although the merit of the analysis has been questioned, only by having alternative data analyses published in peer reviewed journals is it possible for the UK Governments to consider amending the policy. Nevertheless, we have contacted Donnelly et al previously in an attempt to meet and to find common ground, but our attempts were rebuffed. In order to give the reader a clear idea of the applied implications of both our re-evaluation and the peer review comments, we have added some text to the conclusions: “Accordingly a very substantial number of publications that rest extensively or completely on RBCT statistical analyses may require major qualification or retraction. The justification for lethal control of badgers to-date appears to have been based upon basic statistical oversight.” Also there is a reproducibility crisis in science. Therefore it is important for these issues to be published as we believe they provide an exemplar of a major driver to the reproducibility crisis and misdirection of disease epidemic management.
Badger Crowd Comment: A scientific seminar and evening presentation on the work of Paul Torgerson and his team (then a pre-print) was organised in Oxford in November 2024 in order to allow debate with the RBCT scientists. All declined the invitation. DEFRA and APHA sent no representatives. Natural England sent one staff member but gave no feedback. Badger Crowd very much welcomes the reviewers suggestion to hold a “proper investigation…to establish an agreed position involving all parties.”
Reviewer: Comment 1) Section 2.1. I agree with the authors of the current contribution here that use of an offset here is likely a requirement, and that the comments from the Mills et al. (4) are naïve at best – it isn’t helpful to think of an offset as equivalent to setting a regression coefficient to 1.0, as of course the issue is that this is a log-linear scale and the point is that (under the Poisson) we assume proportional rates. I agree that it does not seem to make sense that the herd breakdowns vary only very slightly (the parameter value of 0.04) with the number of herds, although I would caution here only that it is possible some other variable/term in the model might be related to the number of herds, hence suppressing the parameter value (when including number of herds as a regression term rather than as an offset) owing to collinearity.
Torgerson: This is quite possible, and the collinearity is likely to be between the co variates of “triplet” and “baseline herds at risk”. Hence the motivation to explore the results of models where triplet was removed (which always resulted in a considerable reduction in AICc). Although it is not clear if the reviewer required a response to this statement, we have inserted the following text into the manuscript “The removal of “triplet” may remove any hidden effects possibly due to collinearity with number of herds, as well as substantially reducing the number of covariates and hence largely eliminate the issue of over fitting.”
Reviewer: Comment 2) I have personally written (Brewer et al, 2016 – https://doi.org/10.1111/2041-210X.12541 ) about the dangers of relying on the theoretical distinctions between AIC/AICc and BIC, so it should be no surprise that I share the current authors’ suspicions on the preference expressed in Mills et al. (4) for BIC. Also, why are the AICc values for Models 1 and 3 so much higher than the null model in Table 1? Is this just a feature of the small-sample correction? Otherwise I would not expect this at all (if I’m understand what the null model is, correctly); in the absence of other explanations here, given the high number of parameters in models 1 and 3 I would suspect poor model fitting with inflated variances due to collinearity. So, I agree with the current authors here, on the basis of the evidence in front of me (Sections 2.2+2.3, Table 1, supplementary material).
Torgerson: This issue is well taken. This was part of our arguments. Although perhaps not completely clear. We have edited the relevant text which now reads “Brewer et al (16) have written about the dangers or relying on theoretical distinctions between AIC/AICc and BIC. Nevertheless, Mills et al. (4,5) state “…a wide array of statistical techniques and study periods allows us to make robust conclusions regarding the effects of proactive badger culling which are informed by consistent scientific evidence from trial data, irrespective of which approach to statistical inference is taken.” This is demonstrably untrue. The analysis of “confirmed breakdowns” (OTFW) show that results are highly dependent on the approach to statistical inference and information criteria used. However, absence of any cull effect on the incidence of bTB, when total breakdowns are considered, is robust, irrespective of statistical method.”
Reviewer: Comment 3) The discussion on Bayesian models claims that the authors of Mills et al. (4) made coding errors. I do feel that then Mills et al. should be able to examine and (if relevant) correct these errors, and formally issue a correction in the pages of the journal. Otherwise, I don’t feel I have sufficient information to comment further here.
Torgerson: Here the reader needs to refer to both the coding on GitHub, which is where Mills et al have made their statistical code available and the code we have given in the supplementary material. We give an example here. In Mills et al, they claimed an offset was used with the following R code: rs1aB←stan_glm.nb(Incidence~Treatment+log(hdyrsrisk),+log(Hist3yr), offset = log(hdyrsrisk), prior_intercept=normal(0,10), prior=normal(0,10), data = rbctconf, refresh=0) Here you will note (in red) that log(hdyrsrisk) appears twice in the code, both as an explanatory variable and an offset. The effect of this is to shift the parameters of log(hrdyrsrisk) by a value of 1, whilst other parameter values remain unchanged, thus effectively having no offset. The correct code if a parameter value is to be fixed as an offset is: rs1aB<-stan_glm.nb(Incidence~Treatment+log(Hist3yr), offset = log(hdyrsrisk), prior_intercept=normal(0,10), prior=normal(0,10), data = rbctconf, refresh=0) or alternatively: rs1aB<-stan_glm.nb(Incidence~Treatment+offset(log(hdyrsrisk))+log(Hist3yr), prior_intercept=normal(0,10), prior=normal(0,10), data = rbctconf, refresh=0) We refer the reader to our supplementary material where it is fully explained together with the other errors in the code of Mills et al.
Reviewer: I agree with the current authors’ concerns on the statistical audit. I would go so far as to say that, given the important of the topic of this discussion, any audit should be carried out openly and transparently.
Torgerson: We have added short text at the end of section 4 “ It is important that trials include an audit that is open and transparent.”
Reviewer: Comment 5) Section 5 on the neighboring area study – again, from what I can see here, I would broadly agree with the concerns of the current authors.
Torgerson: No response required
Reviewer: Comment. 6) To clarify; I have no issue with the modelling of counts, as the use of a Poisson-form log-linear model is, in effect, modelling rates. To be more precise, I would suggest that the problem is not that Mills et al. (4) modelled counts, but that they did not properly scale those counts by use of an appropriate offset – and again, I am saying this on the basis of the evidence of the current work (only).
Torgerson: Here the reviewer appears to be agreeing with our approach by using the offset. But for clarity so readers can see the derivation of the offset (in the Poisson log-linear model) in our previous manuscript where there derivation is explained. Thus we have inserted the text “The mathematical derivation of the offset is explained in our previous manuscript on this issue (3).”
Reviewer: Comment. 7) Finally, I would like to address the quotation from Donnelly (16): “the suggestion of requiring independent replication of specific statistical analyses as a general check before publication seems not merely unnecessary but a misuse of relatively scarce expertise”. The point to me here is not that work should be “replicated” as such, but that work should be verifiable. The authors of Mills et al. (4) have apparently made their work – at least that related to the 2024 journal papers – available openly, and this is the key; openness and transparency are vital. I would even go as far to say that, in such a contentious area as this, it is naïve to imagine that a single analysis by a particular group of scientists should be seen as sufficient.
Torgerson: Yes we agree, which is one of the issues with the original RBCT proactive cull statistical findings published in 2006, which was led by Donnelly: it was a single analysis by a particular group of scientists, and the Mills et al papers are also led by Donnelly et al. We think this is obvious and it should be verifiable. Nevertheless we have modified the text surrounding the quotation of Donnelly (16). It now reads: The position of Donnelly (17) that “the suggestion of requiring independent replication of specific statistical analyses as a general check before publication seems not merely unnecessary but a misuse of relatively scarce expertise”, needs revisiting. This case underlines the need not only for rigorous checks of statistical analysis but also validation of the statistical models and assumptions used within submitted manuscripts to verify them.
Badger Crowd Comment: For the last 6 months, Sir Charles Godfray and his ‘expert’ panel have been reviewing badger cull and bovine TB science published since 2018. Godfray was involved in the RBCT audit, the 2013 restatement of badger cull science and the 2018 science review. In other words, the single analysis (Donnelly 2006) that has supported the badger cull policy is being reviewed by (largely) the same ‘particular’ group of scientists who have been associated with the work for nearly 20 years. Donnelly herself has been ‘recused’, but has been replaced by another Oxford statistician from the same department. There is no outside scrutiny, and there is a case that there has been no “proper investigation ….to establish an agreed position involving all parties” as recommended by the peer reviewer. A proper investigation would be free from conflict of interest. Defra have refused to address this issue over the last six months.
In case you missed the point of all this, the new Torgerson paper shows how for multiple reasons that there is no evidence that culling badger delivers a disease benefit of bovine TB control in cattle herds. The current ‘closed shop’ of science at DEFRA has fallen flat in the past and should not be allowed to continue. They are selecting the scientists and science that they want to suit a civil service agenda and they don’t want to admit that they have been wrong for very many years. It is a flagrant example of policy driven science. And everybody is losing out because of it: the public (because of the enormous costs of policy), the farmers (because it is a policy that can never achieve its aims) and the badgers – because they are being inhumanely killed in huge numbers.
This intolerable situation cannot be allowed to continue. Badger culling must stop now, and an independent investigation or inquiry must be set up.
A prominent ecologist says an independent assessment of the latest study on badger culling is a “bombshell” takedown of the government’s evidence used to justify the policy. Tom Langton, a badger expert, said the conclusions by a top statistics professor should prompt the government to end the programme of shooting badgers to try to eradicate bovine tuberculosis (bTB).
Professor Mark Brewer, director of Biomathematics and Statistics Scotland, who reviewed the paper, praised the openness of earlier papers but wrote: “I would even go as far to say that, in such a contentious area as this, it is naïve to imagine that a single analysis by a particular group of scientists should be seen as sufficient.”
A study by Mr Langton and colleagues published by the Royal Society criticised scientists who believed badger culling was successful in reducing bTB, claiming they had made coding errors.
In the new study, Prof Paul Torgerson wrote: “The justification for lethal control of badgers to-date appears to have been based upon basic statistical oversight.”
Last week, The Independent revealed that government body Natural England had this year re-authorised supplementary licences to continue badger culls across England – against advice from their own scientific chief. The new culls will lead to an estimated 5,000 badgers being shot dead. The government has already begun establishing teams to increase badger vaccination and launched a badger population survey. It announced on Wednesday that badger TB vaccinations rose by 24 per cent across England last year, to what it said was a record high, with 4,110 badgers being vaccinated.
But controversially, ministers have also reconvened a panel of experts led by Prof Sir Charles Godfray, who has long backed culling and assessed the randomised badger culling trial (RBCT), concluding that culling reduced the spread in bovine TB.
Prof Torgerson wrote: “A very substantial number of publications that rest extensively or completely on RBCT statistical analyses may require major qualification or retraction.” And Mr Langton called for the earlier papers, on which successive governments have relied for evidence to continue culls, to be retracted.
He said: “The independent reviewer’s views should help take a wrecking ball to a large volume of accepted badger-culling science. “This shows how misjudgement can create bad government policy, if statistics are not checked properly and brings to life the many claims that the public have been cheated over badger culling for over a decade.”
Badger lobbyists argue that more scrupulous hygiene on farms reduces TB. The Wild Justice organisation, jointly led by naturalist Chris Packham, together with the Badger Trust, have won permission for a full judicial review of badger culling. The RBCT, which ran from 1998 to 2005, suggested a reduction in TB infections in cull zones, but its findings were disputed because of the “perturbation” effect, where badgers from targeted families moved further away from their natural areas, potentially carrying disease risk with them. It’s estimated 250 papers have been published using the results of the RBCT.
Epidemiologist Prof Christl Donnelly, professor of Applied Statistics at Oxford University, told The Independent that in the light of recent correspondence they would make some minor tweaks to some of their models.
“Crucially, the position does not change: repeated widespread badger culling can reduce risks of bovine TB to cattle inside culled areas, while increasing risks to cattle on nearby unculled land,” she said.
A spokesperson for the Department for Environment, Food and Rural Affairs said: “TB has devastated British farmers and wildlife for far too long.“We are rolling out a comprehensive TB eradication package that will allow us to end the badger cull and stop the spread of this horrific disease.
“This includes launching the first ever national wildlife surveillance programme to better understand the disease and work to increase badger vaccination at pace.”
Government badger cull policy has rested all but entirely on the RBCT analyses. It is the science that DEFRA has used to create policy and in court to defend their decisions to experiment with badger culling. The RBCT claimed badger culling can reduce bovine TB in cattle; very many subsequent studies are heavily derived from it.
Disease benefits that have in recent years been ascribed to badger culling by civil servants and politicians are in reality, far more likely due to implementation of additional cattle measures that were put in place before or at the same time as culling. But Government scientists continue to infer that badger culling has caused a reduction in disease, simply because this is what was “predicted” by the results of the RBCT. its classic confirmation bias.
Below is a chronology of some key RBCT publications.
Inexplicably, the Natural England rationale for licensing the supplementary badger culls in 2025 year did not take the Torgerson et al 2024 preprint into consideration. This is despite considering un-peer reviewed reports this year, and preprints (notably Mills et al 2024) last year.
So although the peer reviewer (Prof M. Brewer, Director of Biomathematics and Statistics Scotland) of Torgerson et al (2025) favours this new evaluation, which concludes that “The justification for lethal control of badgers to date appears to have been based upon basic statistical oversight.”, it was not considered in the cull licensing for 2025. The peer review comments for the new Torgerson et al. Comment paper are available from the online link, and are well worth reading in full.
The justification for badger culling has been shown to be wrong in so many ways. Badger culling must stop immediately, on the basis of scientific evidence.
In response to the new scientific paper published in Royal Society Open Science today, Natalie Bennett has re-iterated the Green Party’s call to bring an end to badger culling. She is quoted as saying:
“The Green Party has long said that the badger cull is cruel, ineffective in controlling TB in cattle, and unscientific, and here is a demonstration of particularly the last.”
“Policy should not be made, or continued, on the basis that ‘we must do something’, even if that something is known either to not work or be actively harmful. Yet that is the position the government is now in.”
“The science is clear that tackling biosecurity and testing in cattle is the only solution to this issue that is causing heartbreak and loss to so many farmers.”
“I repeat our calls for an immediate end to the killing of badgers in this terribly nature-depleted nation.”
The London based Royal Society have published analyses that show how key aspects of methodology of the Randomised Badger Culling Trial (RBCT) published in Nature in 2006 were misdescribed and used implausible analytics. Original statistical appraisal that RBCT authors had claimed was too robust to require checking, was actually fallible, once clearly explained and tested.
The published Comment paper, addresses two scientific papers, also published in Royal Society Open Science in August 2024 by postdoctoral student Cathal Mills, supervised by Head of Department of Applied Statistics at Oxford University Professor Christl Donnelly, and Professor Rosie Woodroffe of the Institute of Zoology, (Mills et al I & II 2024). This work sought to defend the original analysis of the Randomised Badger Culling Trials (RBCT), (Donnelly et al 2006), which had been challenged by a full research paper published in Nature Scientific Reports in July 2024 (Torgerson et al 2024). A peer reviewer characterized one pivotal choice made in the two Mills et al. papers that tried to uphold the 2006 findings, as ‘naïve at best’.
Professor Paul Torgerson, Head of Epidemiology at the Zurich University Vet School, has led a team to undertake a detailed reanalysis of the original RBCT analysis. Papers derived from RBCT work have been used since 2013 by the Coalition, Conservative and now Labour Governments to justify badger culling. Labour however have called it ineffective, but without detailed explanation and have issued a new cull licence. Subsequent academic papers have relied heavily on the ‘ground zero’ Donnelly et al. 2006 publication to continue to claim that culling produces a disease benefit in cattle.
In Torgerson et al. (2024), and now also in the newly published and reaffirming Torgerson et al. (2025) “Comment” on the Mills et al (2024) papers, the most statistically and biologically plausible analytical options showed no evidence to support an effect of badger culling on bTB herd incidence. This is consistent with the 2022 analysis (Langton et al 2022) of part of the subsequent industry led badger culls in England (2013-2019), that was unable to detect any disease control benefit.
The “Comment“ also infers that the so-called “perturbation effect hypothesis” no longer holds convincing statistical support. This hypothesis first suggested in the 1970s was of badgers becoming frightened and disturbed (due to the catching and killing of them) consequently dispersing. Then directly or indirectly, badgers were alleged, to be responsible for multiplying the transmission of bTB to somehow cause half of TB cattle herd breakdowns. This mechanism was used to try to explain the claimed effect from the RBCT analysis.
The entrenched understanding of the role of badgers in bTB transmission to cattle over the last 20 years or so is further undermined and finally departs from any empirical support, sending a shockwave through beliefs that have become ingrained in farming, veterinary and Government thinking, where a high level of denial has already been in evidence since uncertainties were raised in 2019.
The implications of the new analyses are enormous, undoing extensive perceptions within multiple stakeholders that badger interventions are fundamental to any policy to control bTB in cattle. Whilst it clear that bTB introduced to wildlife from cattle is shared between wild mammals such as badgers, deer, rats and even domestic cats, exchange between wildlife and cattle has not been shown with sufficient precision in genetic studies to provide confidence. Infected wildlife may result simply from them being ‘spillover’ hosts, where infection dies out once disease is tackled in cattle. New cattle infections continue to occur due to poor testing sensitivity failing to identify disease, the incorrect designation of herds as ‘TB-Free’ when still infected, and continuous trading of infected calves and yearlings. The ongoing bTB crisis has cost the UK and Ireland an estimated £2 Billion in public payouts and lost productivity over the last 20 years alone, including over £1 Billion in England and Wales since 2013.
In 2024 the DEFRA Minister Daniel Zeichner invited Professor Sir Charles Godfray at Oxford University, to reconvene his 2018 review panel to consider the latest relevant scientific publications. Godfray, was involved in the statistical audit of the original RBCT analysis and in a 2013 report that appraised RBCT badger culling science, and a review in 2018 that recommended badger culling should continue. He has consistently endorsed RBCT statistics and badger culling.
The new paper and reviewer comments are available to read here.
Quotes from authors
Paul Torgerson, Professor of Veterinary Epidemiology at the Vetsuisse Faculty of the University of Zürich who has led the independent group said:
“The significance of our findings extends to several dozen papers written since 2006 that use the 2006 findings to build a theoretical case that badger interventions are a necessary part of bovine TB control in cattle, when they are not. Much work is now needed to highlight this issue by corrections, retractions and other measures to ensure students and practitioners are no longer misled. Bovine TB control must focus on inadequate TB testing and movement control of cattle where the problems are now well known.”
Tom Langton a nature conservation consultant within the independent group who has studied bovine TB control, has coordinated technical and legal scrutiny over badger culling since 2016. He said:
“The Government challenge to prevent further £1 billion spend over the next decade on more inadequate disease control will require fresh thinking and approaches. The Labour Government has rightly labelled badger culling as ‘ineffective’ and must surely now immediately cancel all badger culling licences while an inquiry is launched, as should Government in the Republic of Ireland, where thousands of mostly healthy badgers are also culled each year with no demonstrable reward. The failures of the TB testing system are now so well established it is unfathomable why prompt government action was not taken last year.”
Natural England have confirmed that the nine (9) supplementary badger cull licences issued in 2024 have been authorized for their second and final year 2025, with culling running from 01 June to 31 January 2026.
This is despite Director of Science Dr Peter Brotherton’s concluding advice, that “Based on the evidence, I can find no justification for authorising further supplementary badger culls in 2024 for the purpose of preventing the spread of disease and recommend against doing so.”
He has, as in 2024, been overruled for reasons that will not be made clear for a few weeks, no doubt because if it is a re-run of 2024, the authorizations will also be added to the current legal challenge that our 2024 freedom of information response instigated. DEFRA are making it quite clear to enquirers that they are not involved in the decision making, which is a stretch, and details should come out in the legal papers when the case finally comes to court. Unless expedited however, few badgers could be saved due to the lengthy judicial process.
A further 11 areas may be authorized for the final year of four-year culling and the low risk area cull in Cumbria may enter its second year.
npj Climate Action is an open-access, online journal published by Nature Portfolio. It focuses on research and action related to mitigating the hazardous effects of global climate change. It aims to bridge the gap between scientific research and practical climate action, informing policies at both local and global levels.
A paper entitled “The activism responsibility of climate scientists and the value of science-based activism” (Anguelovski et al (2025)) has recently been published in npj Climate Action. The arguments for the participation of scientists as so-called activists in the development and evolution of government policy are eloquently expressed and hard to disagree with. And these arguments transfer from climate science to many other areas of important environmental science, not least badger culling.
Quoting from this new paper, it is surely sensible that “scientists have the right and responsibility to engage in activism” because “their expertise and ethical responsibility position them well to change policy”. This has not been the case thus far with the science of badger culling, where independent peer-reviewed science has been dismissed by government scientists; the term ‘anti-cull activists’ has been used to try to slur individual scientists (and the peer-reviewers of their publications) and undermine the veracity of work that does not concur with the established Government policy view (see the un-peer reviewed letter in Vet Record, DEFRA press release & CVO blog). No peer-reviewed science has been published since to justify the criticisms made in these pieces. Gideon Henderson has since left his post as Chief Scientific Advisor for DEFRA without commenting further on the matter or substantiating his intervention. Chief Veterinary Officer Christine Middlemiss remains in post.
How refreshing to read the recommendation the “..broader societal role scientists can play should be recognized and respected”. This has certainly not been the case with Government funded badger cull science, where there has been no inclusion of published scientists whose conclusions upset decades of Government funded work. Not only has there been inadequate dialogue, but the only route to release of critical data and policy rationale has been through Freedom of Information requests or grueling legal engagement.
Badger Crowd is also happy to endorse the “call for the support of activists who engage with researchers in pursuit of evidence-based action.” As the paper’s abstract concludes, “Mutually supportive relations between science and civic groups will make science more horizontal, inclusive, and thus legitimate and impactful in the eyes of policymakers and society at large.”
Anguelovski et al (2025) includes a useful reminder of some important historical examples of scientific activists; “Think of Darwin’s debates with religious authorities, Snow’s work on cholera, or Rachel Carson’s Silent Spring. Entire branches of science (medicine, conservation biology) are defined by their activist agenda”.
So, we will look forward to future involvement of allbovine TBactivist scientists in the debate about the efficacy of badger culling and the direction of bovine TB policy. They have an important contribution to make. And it should have happened many years ago.
If you, as a member of the public, activist or scientist, support challenging the flawed science behind the badger cull and want to see a parliamentary debate on the issue, please sign the petition linked below calling to “End the Badger cull and adopt other approaches to bovine TB control”:
Prof. Sir Ian Boyd has a book out: ‘Science and Politics’ (politybooks.com, around £20). In it, he devotes several pages to describing the events that led up to the start of English badger culls. He talks of attempts to reign in early plans to get badger culling implemented, when a simple mess-up down to flawed population estimates led to the cull being postponed for a year. He then provides an ‘after the event’ critique of badger culling. Could this be a bit of re-writing of history with the benefit of hindsight, which has shown the inability of its proponents to demonstrate any benefit from the culls? There is no mention of the repeated failures to get a sufficiently good grasp of the veterinary science at the time, or the failure to call-out weak and questionable Government science at the heart of policy.
On February 15th Boyd was the guest of Sir Charles Godfray in Oxford for a book promotion, where bovine TB and badgers was the most mentioned topic, but the wider issue was politics distorting the scientific process in general. His main thrust appeared to be to point the finger at the politicians (‘charlatans’ he calls them in the book) and also at the Royal Society for not effectively educating the politicians. Boyd has clearly been frustrated by his seven-year experience as Defra chief scientist advisor (CSA), working for what he said might have been a ‘bad batch’ of Defra Ministers. But could he perhaps just be trying to hide his own wrong moves in plain sight?
Boyd’s cull?
If you had to pick one person whose name is synonymous with making the English badger culls happen on the ground during the last decade, it is arguably Ian Boyd, who was CSA for DEFRA from 2012-2019. Although the culls were not his concept, the job description required him to ensure that the policy was implemented, and that’s exactly what he did. He was put in post when the plans for two small pilot culls were underway, and he drove them through under Caroline Spelman and then Owen Paterson at DEFRA. Notably, at a National Farmers Union presentation in 2014, he gave a detailed PowerPoint presentation, where he said that there was no question – badgers had to be killed in order to deal effectively with bovine disease in their cattle. The effect of this was to cement the loathing of badgers for a generation in the livestock community, green-light vets to promote the badger blame game and make continued culling easier and illegal culling more likely.
By 2015 an Independent Expert Panel on badger culling was deftly bypassed. Emails released to the High Court would later show how Civil Servants were coached on how to get around legal issues to ensure the full badger cull roll-out from 2016.
The book talk entitled ‘Sir Ian Boyd in conversation with Sir Charles Godfray and Dame Helen Ghosh’ was held at the Oxford Martin building in central Oxford on February 15th. It put Ian Boyd amongst the scientists from the Randomised Badger Culling Trial (RBCT) study that provided the original (2011) policy justification for badger culling. His book, basically an insiders guide to how politicians and scientific advisors rub along together, was live-screened and put online too, (here). The audience, described by Godfray as ‘prestigious’, included a range of government and ex-government employees who had seen Boyd in office. SirJohn Krebs (the main architect of the RBCT) was there alongside Christl Donnelly who did the controversial statistics of the RBCT, and the Emeritus Professor statistician Sir Bernard Silverman who has replaced Donnelly on the recently re-convened bovine TB review panel to be run by – your guessed it – Charles Godfray. Gideon Henderson who took over the role of CSA at DEFRA after Boyd, was also there. Helen Ghosh who was Director-General of the National Trust during the Badger Culls, made up the third member of the discussion panel, and the meeting took questions from a select few, with one or two further questions from the floor at the end.
Sir Charles Godfray, Sir Ian Boyd, Dame Helen Ghosh
The ‘scientifical political predicament’
Boyd’s short introduction made it plain that his book was aimed at getting a debate going, and that he was on a ‘good-guy’ mission. When he accepted the Chief Scientific Advisor role at DEFRA, he said that there had been no help to give him insight into what it would be like, and he had to learn very quickly. He felt he was on a learning curve the whole time, and after he had left he felt he had a duty to share his experiences. The first part of his book, his ‘scientifical political predicament’ (the tensions between scientists and politicians) led him to think that by getting involved with politics, scientists actually become ‘corrupted’. It was, he said, a problem that scientists have to try to solve to make the ‘politics factory’ (the people and space where Government happens) more effective. This included the institutions and structures around Government: NGO’s, industry, lobby groups, etc.
Part two of his book takes this further, and is called ‘Science Corrupted’. It was, he said, “really about trying to take the consequences of the processes that science is involved in, with respect to trying to get its voice heard, and understand what effect that has on science. So it’s the scientifical political predicament being played out”. As chair of the UK Research Integrity Office for the last six years, Boyd felt that a lot of the problems that sit with ‘science integrity’ occur at the politics factory interface, and are partly a result of, and partly driven by that process. Within this interface, Boyd described constructs, such as ‘evidence’, ‘what works’, ‘experts’ and ‘normative research’, and with lots of ‘confirmation bias’ sitting in the research. But he did not distinguish between research that was Government funded and done in-house, and that undertaken by independent bodies. He felt ‘confirmation bias’ occurs mostly in areas of post-normal science where there’s high uncertainty, high demand for results and a lot of controversy. He could have been talking about badger culling, (here). In the mid 1990’s, an impatient if not aggressive MAFF, tore up the veterinary research they did not like and demanded decisive action to cull badgers on behalf of cattle farmers.
‘Marking own homework’
The third part of his book, Boyd said, was called ‘taming the beast’, and about how it might be possible to fix the problem. This would be external to the existing ‘executive, legislative and Judiciary structures’ within Government that look in on how science is used, but were prone to ‘marking their own homework’ to some extent. Hence the continuous degradation of quality within the science being used would be avoided. He felt this would need a lot of hard work and determination, particularly from the scientific community and the leaders within the scientific community.
Helen Ghosh said she had been brought up in the old Department of the Environment, and her Secretaries of State in succession were Michael Heseltine, Tom King, Chris Patton and John Gummer, who had dealt with a lot of very tricky scientific issues. She didn’t recognize, or only recognized partially, Boyd’s characterisation. Boyd then praised Michael Gove (2017-2019) and said he (Boyd) had probably worked through a ‘bad batch’ of SoS’s. There had been good times, but not many, he said (note, before Gove they were Caroline Spelman, Owen Paterson, Liz Truss, and Andrea Leadsom). Ghosh mentioned badgers as being a problem that needed looking at on a ‘systemic basis’ (farming) rather than on a ‘topical basis’ (disease control). The ‘elephant in the room’ however was that if the disease control science been understood and implemented properly, the bovine TB epidemic could have been controlled much sooner. Boyd had failed to get his head around the veterinary science. Badgers and bovine TB were mentioned (although not in any detail) now and again, usually with a nervous smile from those present, many of whom still have considerable ‘skin in the game’.
Emergency ‘car crash’ response
Boyd’s view was that the leadership within the scientific community has to be much more attuned to ‘providing’. Making sure that science gets into the system at a much earlier stage than it tends to do at the moment. With it currently being a sort of emergency ‘car crash’ response a lot of the time. “And it really can’t be. It needs to be involved in designing the car and the road system and all the other things that go on.“ he added. Maybe it was a matter of having science advisors within political parties when coming up with their manifestos, he suggested.
Hindsight
Boyd was asked what he would have wanted to know when he walked into DEFRA’s offices in 2012 and what had he learned subsequently? Tellingly, he said that he would have preferred to have had a better view on how to deal with the badger culling situation. As mentioned above, Boyd’s book has what some might call selective reporting on this issue. As mentioned, he now frames himself as reticent towards badger culling. He said badger culling was something of a ‘wonderful example’ of the scientifical political predicament “and it’s still ongoing, you know it’s one of these things that just rolls on and on and on. And Gideon’s there, Gideon [Henderson] will be dealing with it right now, you know and John [Krebs] is here, and John dealt with it a lot.” It will go on and on and on. I don’t think there’s one solution to it. But I wish I’d known a lot more about the technical details when I walked in.” So do the badgers. And the cows and farmers. And the second ‘elephant in the room’ was Boyd (and previously in 2007 David King the Gvt. CSA), failing to check the statistics of badger culling in sufficient depth – King didn’t quite dig deep enough. If either of them had, they would have discovered how weak the association between badgers and bovine TB in cattle truly was. Krebs and Donnelly, sitting in the audience were not going to comment, having created the science that has been used and providing the endorsements politicians needed to set Boyd up to launch mass culls.
Hocus Pocus
Boyd went on to say that he worried about the extent to which there is compromise on the quality of scientific knowledge and argument. He referred to ‘indigenous knowledge’ in the biodiversity and environmental space, and how ‘indigenous peoples’ do know a lot about their environment and actually can bring an immense amount of information to bear on it. This was a bit obscure, but perhaps an oblique attempt at characterising those outside Government/University circles. Some information was ‘Hocus Pocus’ he said, “and we need to be able to identify the difference. We need to identify the good stuff from the bad stuff, or the reliable stuff from the unreliable stuff.” But that was his job wasn’t it?
Boyd bemoaned an ‘awful lot’ of evidence that sits around masquerading as high quality when it is actually quite low quality, but did not give examples. Boyd felt it was “really hard when in a position of having to advise a minister to use this evidence or that evidence, to know what is good and what is bad. “ Hmmm……
He continued “In the end you often have to make a judgment about, well, where does it come from, is it reliable source, those sorts of things, or you know, looking at looking at scientific paper and understanding, particularly the methods, are the other methods reliable or not. But even that actually sometimes masquerades as high quality when it’s actually quite low quality” Was that recognition that there has been an excessive reliance of work from sources with the right ‘pedigree’, without sufficient scrutiny?
This seemed to be as close to a confessional over badger culling as you could get. Boyd had little experience with veterinary science or cattle management in 2012 and as a ‘newbie’ had accepted, without enough scrutiny, the ‘Oxford’ science and submitted to the NFU brow-beating approach. Did he only realise, or accept his lack of understanding once he had left his post? Or has he held his confessional back for a reason or two.
So what was he doing by writing his book? Putting it out to all that he was a victim of a broken system? Hints of contrition? Was this just an elaborate ‘I got it wrong’ moment – a cathartic admission to purge his conscience and temper his legacy in an era that will be named as a defining one in UK environmental demise? The badger culls (and bovine TB muddle) need not ’roll on and on and on’. But Henderson, the new CSA, picked up the torch from Boyd and still no-one in Oxford wants to be the first to admit, or even mention the overwhelming uncertainty around their badger cull science. And, oh yes, Henderson is an Oxford man too…
Standards being stretched
Boyd’s thesis was that there is need for an official authority to be able to say ’this person is reliable’ and ‘this person isn’t reliable’. As President of the Royal Society of Biology, he said there was an authentication process (Chartered Biologist) that he personally does not use, but his view was that it should be used a lot more. There was scepticism from the audience. Gideon Henderson, who had suffered his own banana skin moment over badger culling data (here) wanted to know how corrupted he personally, and others had become? Presumably he had read Boyd’s previous writings on departmental tribalism (here). He wanted more detail, and to understand the nature of the corruption? Awkward.
Fiona Fox from the Science Media Centre made a remark that seemed more like a jibe, and with a distinct sarcastic edge than a question, possibly not understanding the way SMC gets used by civil servants; “…should academic scientists be expected to understand the policy process and understand what hell you are all clearly going through?” Unabashed, Boyd said that he felt ‘his standards’ were being stretched to some extent, and it had taken quite a lot of will, and self-discipline, to make sure that the basic scientific standards that he had been taught and had practiced for a very long time, were sustained and maintained. On corruption he said that people who get involved who are ‘not so wise’, could fall into a trap, which is basically to produce what he called ‘normative science’. Otherwise sometimes referred to as ‘policy-based science’. This is science that is helping to drive policy in a particular direction, and that he confirmed was what he meant by corruption. You could look at plenty of DEFRA agency constructs that fit this bill, but complying with civil service protocol, Boyd was not naming names of anyone still in post. Did Henderson really not realise he just might fall into the category of ‘unwise person’? The polite tensions in the room were palpable and it was not clear who was having dinner with whom afterwards. The wrinkled noses in the audience were those of the civil servants who know about the problems and observe a protocol not to boat-rock once they have left office . At least Boyd deserves credit for speaking out, albeit a bit too late.
Boyd continued “I don’t really mean individuals are making an overt decision to undermine science. I think that there is an invidious underlying process that draws them in, in order to be able to produce the results that somebody else wants rather than the results that actually really are needed. So that’s what I mean by it. So it’s not a personalized criticism.” He unconvincingly wriggled around the tribal fear culture. His ‘tribalism’ thesis was the way in which, as a whistle blower, he was balancing being seen to seek honest reform (within the den of thieves in Parliament) with risking the extensive ‘pissing off’ of those outside Westminster, who might still lean over and damage any future ambitions.
Prof Bernard Silverman (statistician and renounced curate now standing in for recused Christl Donnelly in the Godfray bovine TB review panel) was the Home Office’s Chief Scientific Advisor, overlapping with Boyd’s tenure (here). He asked about the role of the Royal Society, of which he is a Fellow. Boyd went into overdrive: “ The problem is the Royal Society actually. And I’m saying that in a public domain. Where you have the premier organization which has a capacity to really knock on the highest political door in the country. And it does need to do more of a coordinating activity. I have no doubt about that at all. But it doesn’t, and I’ll leave it at that. And I see you nodding.” Boyd thought that science would do well to look at some of the other professions and how they manage quality control within those professions; the scientific community could come up with a new system. But it needed to be valued by the policy profession.
Also present were Claire Moriarty, past permanent secretary in DEFRA during Boyd’s period of office, Claire Craig who was Director of the Government Office for Science, Jim Naismith, Head of The Mathematical, Physical and Life Sciences (MPLS) division at Oxford University and John Beddington (London Zoo).
So what can be taken home from all of this? Basically, there is continuing pressure to produce results to fit a political agenda, mistakes are commonplace, they continue to be made, and the way to prevent the same thing from happening in the future is far from clear. Learned societies need to step-up, but acceptance of the problem is not universal. One thing is certain however; badgers, cows and the livestock industry lost out from the tangle of ‘Science and Politics’ before, during and after Boyd’s time in office, with 2014 targets now missed. Until those responsible take a good look at themselves and the mountain of hindsight now available, disgraceful waste will continue.
Government to review the last six years of bTB science for its ‘refreshed’ bovine TB strategy
On 30th January 2025, Defra issued Terms of Reference (here) for the ‘comprehensive new bovine TB review’, that was announced last August. This included details of a scientific panel which will be reviewing ‘new’ evidence that has become available since the last review was published in 2018.
How objective will the new review be?
The panel, that last month began reviewing new evidence for the ‘refreshed’ bovine TB strategy, is largely a reprise of those who undertook the last review back in 2018, with one exception. The panel will be chaired, as previously, by Professor Sir Charles Godfray, University of Oxford. He will be familiar with the current scientific views of those whose work has been used to maintain badger culling for the last 12 years. He was personally involved in the statistical audit of the Randomised Badger Culling Trials (RBCT) (1998 – 2005), and so is extremely close to the discussion of issues relating to questionable statistical approaches raised since the last review.
As before, Godfray will be supported by Professor Glyn Hewinson CBE of Aberystwyth University,Professor Michael Winter OBEUniversity of Exeter and Professor James WoodOBE of University of Cambridge. Wood has been vocal on TV and radio in his long-term support for Government publications that have suggested that badger culling might be working.
Professor Sir Bernard Silverman FRS, Emeritus Professor of Statistics at the University of OxfordUniversity has stepped in to replace Christl Donnelly, Professor of Applied Statistics at OxfordUniversity, who requested to be ‘recused’, for reasons that have not been stated, but may relate to recent scientific discussion over statistical elements of the RBCT. As one of the statistical auditors of the RBCT, Charles Godfray made recommendations in 2004 for tighter control of the data and analyses. Donnelly (et al.) statistics from the Randomised Badger Culling Trials (here) have been challenged in a new scientific paper by Torgerson et al. (here). And the debate has continued with Mills et al. (here) and (here) and Torgerson et al. (here). Whilst it is welcome that the ongoing dilemma will be reviewed, is the proper approach to have Oxford academics looking into an Oxford issue? Silverman describes himself on his CV as “Recognised as a world leader through ratings and awards. Wide experience within government, as chair or member of boards and committees and as a departmental chief scientific adviser, with specialist expertise in national security, modern slavery, official statistics, etc.”. Notably, he was on the panel of the Anderson Inquiry into the handling of the Foot and Mouth Epidemic in 2001, so has some experience of epidemiology.
The panel is expected to report their findings by the end June of 2025. Which is unfortunate for all the badgers that will be killed in the culls for which licences will be issued from June 1st (and September 1st) 2025. And for those that are victims of the escalating illegal culling that has been reported since ‘legal’ culling began.
One cannot help but think that if Labour had really wanted an objective review of the science around bovine TB and badger culling, they would have asked an independent set of scientists with less ‘skin in the game’, and perhaps more distanced from Oxford to undertake such a vital review. But once again it seems that it is largely the same set of academics who will be looking at the science in which they personally have a historical interest and potentially, future stake.
Defra have announced a £1.4 million badger vaccination project in Cornwall (here) suggesting that they may have already made their mind up on the science evidence; they are still treating badgers as a central issue in the control of bovine TB, despite the growing doubt. Yet they are still unable to provide any certainty that this is the case. Some are making robust claims about whole genome sequencing and what it can show, whilst others are modelling what they think might be happening using outdated assumptions and unproven associations. Meanwhile, the strongest evidence of inadequate control points to ineffective cattle testing being the crucial driver of bovine TB, and the solution must therefore lie with cattle controls.
The Government’s TB Eradication Strategy allows the continued killing of badgers, a protected species, until the end of this Parliament, despite the Labour manifesto calling the cull “ineffective.”
We believe the badger cull is unjustified and must end.
Some research has suggested culling results in a reduction in bovine TB (bTB) in cattle. However, there are concerns about the methodology used. Other research, which has been peer reviewed and published, shows no evidence that culling badgers reduces confirmed bTB in cattle. Over 230,000 badgers — many healthy — have been killed, disrupting ecosystems without solid scientific justification.
We call for an immediate end to the cull and the implementation of cattle focused measures to control bTB, rather than what we see as scapegoating wildlife.
We fully support this petition and would encourage you to add your name. Encourage others who care about badgers, effective disease control and the correct interpretation of science to sign too. Let’s see it reach 100,000 signatures & get a parliamentary debate.
The quotes in the table below are taken from the APHA county epidemiology reports recently released. Progress is clearly not on target. As seen in Oxfordshire (see here), bTB in the Edge Area is not being addressed with sufficient resources or the right approaches. The lack of adequate testing is so glaringly obvious it is beyond belief that this situation is being allowed to continue. The bovine TB eradication policy is in tatters not just in the HRA and LRA but in the Edge Area too.
County
Progress
Going Well?
Berkshire
“Looking at the recent trend, the likelihood of achieving a herd prevalence of less than 1% OTF-W incidents in Berkshire by 2025 is low.”
No
Buckinghamshire
No prediction
?
Cheshire
“..the prevalence (4.4%) in 2023increased marginally compared to 2022. OTF county status will not be achieved by 2025,but with the use of all available tools to identify and to reduce the burden of infection, it might be possible to achieve OTF status by 2038.”
No
Derbyshire
“Based on current information, achieving OTF status is not conceivable for Derbyshire by 2025. Residual infection continues to be a problem in Derbyshire. The reasons for this are unclear, may be multi-factorial, and is likely to include herd type, wildlife populations, farming practices and proximity to the HRA county of Staffordshire.”
No
East Sussex
“The increase of prevalence rate from 2022 in addition to the geographical extension of the endemic area (HRA prior to 1 January 2018) suggests that East Sussex will not be able to achieve OTF status by 2025. The prevalence and incidence will need to have a considerable reduction through the next 10 years to ensure that OTF status in the county could be reached by 2038.”
No
Hampshire
“The likelihood of achieving a herd prevalence of less than 1% OTF-W incidents in the county by 2025 is low.”
No
Leicestershire
“Although the herd incidence declined again in 2023, it is unlikely that Leicestershire will achieve OTF status by 2025.”
No
Northamptonshire
“Despite the declining herd incidence and prevalence trends over the last 3 years in Northamptonshire, it seems unlikely that the county will be eligible for OTF status by 2038.”
No
Nottinghamshire
“Additionally, prevalence in Nottinghamshire at the end of the reporting year was 1.7%. It seems unlikely for Nottinghamshire to become eligible for OTF status by 2025, as set out in the strategy for achieving OTF status for England, published in 2014. However, if the disease trend continues to decline as a result of effective disease control measures it is possible Nottinghamshire will achieve OTF status by 2038.”
No
Warwickshire
“Official-TB-Free status (OTF) for Warwickshire will not be achieved by 2025, as set out in the ‘Strategy for Achieving OTF Status for England’, published in 2014. However, progress is being made and the outlook is positive.”
No
Recurrence
‘Recurrence’ is where bovine TB returns to a herd after a period when it has not been detected by periodic testing. Recurrence is the result of residual infection, ineffective testing and cattle movements, (with the odd unevidenced nod to wildlife). Recurrence is now recorded consistently across the Edge Area and the High Risk Area, and it is the reason why the Edge Area is unlikely to be TB free by 2038. APHA diverted gamma testing in 2021 to herds with a history of recurrence and persistence, at the same time reducing parallel testing of gamma alongside the skin test in OFT-W (Officially TB Free Withdrawn) herds, resulting in early undetected disease remaining in herds throughout the Edge Area.
It’s interesting to note that ‘Overall Recurrence’, ie recurrence during the herd’s lifetime, has been added to the recently published epidemiology reports (see below). Previously, recurrence has only related to the previous 3 years. ‘Overall Recurrence’ reflects the true seriousness of the epidemic.
And alongside the reality of the problem of Recurrence, the APHA are still blaming badgers for significant disease transmission without evidence, and still claiming disease benefit from badger culling without evidence.
A prominent ecologist says an independent assessment of the latest study on badger culling is a “bombshell” takedown of the government’s evidence used to justify the policy. Tom Langton, a badger expert, said the conclusions by a top statistics professor should prompt the government to end the programme of shooting badgers to try to eradicate bovine tuberculosis (bTB). 
A paper entitled “The activism responsibility of climate scientists and the value of science-based activism” (
Prof. Sir Ian Boyd has a book out: ‘Science and Politics’ (politybooks.com, around £20). In it, he devotes several pages to describing the events that led up to the start of English badger culls. He talks of attempts to reign in early plans to get badger culling implemented, when a simple mess-up down to flawed population estimates led to the cull being postponed for a year. He then provides an ‘after the event’ critique of badger culling. Could this be a bit of re-writing of history with the benefit of hindsight, which has shown the inability of its proponents to demonstrate any benefit from the culls? There is no mention of the repeated failures to get a sufficiently good grasp of the veterinary science at the time, or the failure to call-out weak and questionable Government science at the heart of policy. 
