A recent meeting about badgers and bovine TB (bTB) at the Zoological Society of London (ZSL) was followed closely by the belated publication of what is barely disguised government propaganda.
The publication models the effects of badger culling on new herd bTB breakdowns following four years of extensive badger culling, including in Gloucestershire and Somerset (Pilot culls 1 & 2).
The ZSL meeting presented details of a small study in Cornwall, including data for one place where badger culling has been carried out and badgers observed. Results showed that, as with other species such as foxes, and as shown in other badger studies, once persecuted surviving individuals dispersed more widely.
At the meeting, the Cornish badger populations researcher Rosie Woodroffe is reported to have criticised one aspect of the Godfray Review, the 2018 inquiry into the current bTB policy that the government is apparently about to comment on and implement. The review posed more questions than it answered.
Concern was expressed that the review's suggestion for comparison of mass badger vaccination with supplementary culling (continued culling after the first 4 years of culling) in any forward strategy would be biased. Such bias would be due to many of the remaining badgers in cull areas being cage trap-shy.
A better comparison, Woodroffe reported, would be between data from a vaccinated area and an un-culled comparison area.
This raises two important queries. Firstly, over the government response to the Godfray Review, and secondly over the ability of the government’s 2011 bTB policy to feedback with any accuracy upon its own progress in the fight against bTB, by killing badgers.
Defra measures infection by monitoring bTB: including project SE3131 conducted by The Animal and Plant Health Agency. It tries to count new herd breakdowns via the SICCT test that is known to be unreliable, and it counts herds that are certificated ‘clear’ of bTB when the unreliable test says so.
Many ‘clear’ herds, however, are still infected (due to low sensitivity of the test) and will go on to spread and perpetuate the disease locally and wherever uncaught infection is transported by lorry.
All, it may be said, that can be done to try to say at least something about what the badger cull might be doing, is to compare new breakdown figures with what is happening in un-culled areas. Un-culled areas are diminishing in number, as culled areas surround and engulf them.
With modelling (that includes altering figures to try to adjust for the effect of other variables), it is not possible to have surety in the level of accuracy of your findings. However, if policy culling is taken as implementation of the Randomised Badger Culling Trials findings alongside other necessary steps, the face value breakdown numbers in pilot culls should speak for themselves with an average anticipated benefit of 16 percent per year.
Generally the more factors that you adjust for, the weaker your confidence in them reflecting the real world. A paper in 2017 (Brunton et al.) analysed just the first two years of culling and was criticised on exactly this point; for adjusting for many potentially confounding variables. Yet despite this, the findings were wrongly presented at the time to the public, more or less as fact, by MPs and Ministers.
The ‘elephant in the room’ is a catastrophic lack of basic statistical confidence before informing the public about data. In effect, the public are being wilfully misled.
Defra’s official position, as determined from government disclosures to legal challenge in 2019, is that for their own thoughts on the power of analysis, the policy requires at least six cull areas to be compared after four years before you can start to make tentetive comment.
Therefore, just to get a basic modelled result that might give you an early glimpse of what just may be happening, but not with any certainty, the wait is until some of the ‘new in 2016’ badger culls are four years old, plus an observation and analysis period – effectively in 2022.
By this time over 200,000 badgers may have been sacrificed. All as a result of a hypothesis that has a good chance of being unsound due to bias; lack of blinding and such statistical factors.
But an even bigger elephant was detected relatively recently, thanks to a final act of the retiring Defra Chief Scientific Advisor Ian Boyd, in June 2019. His written advice was that it will never be possible to distinguish the existence or measurement of directbenefit from badger culling from any other individual bTB intervention. Other interventions include additional and more effective bTB testing, hygiene improvements in cattle sheds and the prevention of infected slurry spreading from causing faecal ingestion of infected slurry.
Boyd indicated that the policy aim is to cull badgers long term, until 2038, and to consider data from the whole of the High Risk Area on a regional basis, but only after such an extended period when badgers have been removed for many years.
A cull with no ‘stop button’ is consistent with fears that the supplementary culling method, devised in 2015, was simply an endorsement of Nigel Gibbens (ex Chief Vet) enthusiasm from the start to copy the culling approach implemented in the Republic of Ireland since 2004. In RoI, past Irish government statements have also tried to link badger culling and herd breakdown reduction.
These statements are very poorly substantiated (if at all), and based on low sample sizes, cause-arguing and presentations that seem heavily biased. In fact, the lower bTB trend in Ireland correlates more closely with cattle measures/testing than with badger culling.
Unlike the UK, the RoI has never relaxed annual herd testing nor did it suspend testing during the foot and mouth disease epidemic. Consequently, Ireland is not suffering the legacy of higher levels of bTB experienced in the UK resulting from Maff/Defra policy decisions of nearly 20 years ago.
The Downs et al. 2019 report was remarkable in that it was accompanied by an extremely comprehensive Defra publicity drive to state that badger culling appeared to be working in Gloucestershire and Somerset. As with Brunton in 2017, the statistical modelling within the paper is tortuous.
In 2017, Brunton showed that assessment of culling impact was sensitive to adding and taking away adjustments, but in Downs, sensitivity analysis is not mentioned, despite multiple adjustments.
What is to be made of the Downs paper? It is an analysis based on data up until 2017, while Gloucestershire herd incidence rose by 130 percent in 2018.
So on one hand the Downs could well be a dead letter. While on the other hand, the government has come clean that it has adopted a policy that says ‘you will never know whether badger culling works in practice or not’, yet at the same time that ‘badger culling is working’ and (but unspoken) there is a need to keep killing until essential approaches (testing, movements and hygiene etc.) are more efficacious.
There has long been suspicion that this was the approach. We now have proof that this is exactly what it is.
In short form; kill the badgers in case it might help, while someone tries to put the essential cattle measures in place. This is the reality.
Defra’s exercises to measure the hypothetical benefits of the cull, (using models it admits may be inconclusive) are being passed to politicians pretending it can be said to be working.
So with George Eustice claiming “the cull is starting to show results ... No one wants to be culling badgers forever” perhaps he hasn’t been told the facts. That the plan is not to know whether badger culling assists or not and to kill badgers beyond his retirement while still not knowing the return, if any.
Perhaps most worrying of all is to see scientists paid now or in the past by government (& who know or should know the above), writing loaded critiques of Downs' Report.
While on the one hand they pick out some of the cautionary remarks in the paper that are underneath the headline, on the other hand confirming either in passing or outright, that in theory the pilot culls are likely to be working and reducing bTB herd breakdown. That’s not what was said in 2013.
This was also done by Christl Donnelly and John Krebs on Radio4 Farming Today on 14 October, exactly as Defra and the NFU would have hoped and wished, by relying on the Randomised Badger Culling Trials (1998-2005).
In doing this, they ignored the fact that on data from two places, nothing can or should be concluded about faint signals until a greater sample size is available. Comparing real differences between two 4-yr cull and control areas (let alone via modelling) is like taking two girls and two boys out of a large school to declare whether girls are taller than boys.
It seems absolutely extraordinary that they chose to do this at such a sensitive time, and that it should be coincide with such a concerted effort to get the popular media, trade (vet and farming) press and Defra-funded outlets to run a PR campaign claiming badger culls to be a significant success. The British Veterinary Association and National Farmers Union rushed out a supporting message. It is hard to think when such a large scale coordinated environmental propaganda exercise was undertaken in England.
The sociology clue
The reason for the government approach may inadvertently have become apparent over the weekend of 12/13 October.
Perhaps coincidentally, a sociologist working for Defra began commenting on social media that preliminary studies suggest that cattle farmers are only willing to undertake essential bTB controls thoroughly, once badgers have been killed and reduced for a number of years. While this was somewhere between known and suspected, it shines a light on two very important things that the English and Irish government might care to consider with some urgency.
Firstly, the refusal of many farmers to cooperate with voluntary cattle measures until badgers are killed. The agri-folklore myth of certain badger culpability with bTB in cattle was very strongly fostered for 20 years before the RBCT and ingrained in the farming community.
It was no secret that even despite the RBCT conclusion that culling ‘could make no meaningful contribution’, culling was adopted part as a ‘carrot’ to try to garner farmer compliance for disease-control related trade constraints that could be severe.
This happened irrespective of the now irrefutable evidence of the chronic failure in the use of the SICCT (tuberculin skin) test, where very many farmers have been given bTB-free status incorrectly and allowed to trade infected stock widely.
Secondly, such ‘carrot’ lead behaviour helps explain one of the more important criticisms of the RBCT and other culling trials in Ireland. This is that in an un-blinded trial (where treatment or lack of it is known to participants), significant effects are caused by the lack of blinding.
So fewer breakdowns in badger cull areas may simply relate to other inseparable variables at play, with badger culling becoming the placebo that government hopes will motivate farmers, whether or not it has any value.
Downs touches helpfully on this crucial issue: “There are other mechanisms at play that amplify effects associated with badger controls. Implementing culling may lead to greater focus on cattle controls, TB testing quality and implementation of biosecurity.”
This is exactly where scientific criticisms of the RBCT have pointed out another major fallibility of that early work and of other field trials of limited strength and clarity. To the list could be added unregistered cattle movements. These days, a scientific trial of badger culling without blinding would be highly controversial.
With the shortcomings of the RBCT comes the controversy of the badger and bovine TB ‘perturbation effect hypothesis’, where badgers are theorised to carry bTB to infect nearby herds with rapidity after culling, to bring about herd breakdown.
While this hypothesis was criticised by government scientist; Sir David King, and his team in 2007, due partly to inadequate statistical power in calculations, it has been debated since then both as fact or fantasy by those for and against badger culling. A danger has emerged however in that as with culling, massively expensive mass badger vaccination could be attempted in some effort to apply the hypothesis to the real world.
Mass vaccination is not to be confused with the worthy local efforts to protect badger populations with vaccination that is practiced by several Badger Groups and Wildlife Trusts. In principle veterinary efforts to remove a virulent non-native disease should be welcome, done carefully as a wild animal intervention. Local schemes rightly defend badgers from imported cattle disease and treat hundreds of badgers a year across several counties.
But this is quite unlike Defra’s policy requiring a nationwide military scale mobilisation of shooters (or vaccinator’s), and vast sums of public & private money, as well as professional implementation teams.
What is known however, is that vaccination has been trialled in north Pembrokeshire Wales (2013-2017) on a large scale with over 5000 badgers vaccinated. It proved inconclusive in relation to bTB reduction in cattle and shelved as a meaningful large scale action. Even if badgers are protected and pass bTB resistance to offspring, the capacity to assist in the battle against bTB is an unknown.
Measures needed to identify the ‘hidden’ bTB reservoir in the herd and to prevent cattle movements are known, but under-implemented due to industry resistance. Scarce resources must surely only be pointed at genuine solutions and the limitations of the ability to measure badger interventions fully grasped. Speculative spending around the crisis is pointless. It is the unimplemented cattle measures that need to be got right.
Comparisons of vaccination with culled or un-culled areas would, as with culling, be scientifically unmeasurable and a wrong turn. Not just because of confounding variables and as yet another action with no measure, but because it would be a further huge escalation of unsafe science in unsafe policy.
They would be an excuse for yet more prevarication, distraction and inaction on the scandal of failed testing and further prolonging a failing policy.
Badger culling and mass badger vaccination should come under the heading of ‘Badger Meddling’. That is, the unsafe practices that, in an unscientific way use massive amounts of public funds to interfere with protected species populations in unquantifiable actions that are not safe experiments.
They are based upon hypotheses created around unknown bias as opposed to direct evidence and have no accurate quantitative measure.
How we have got to this position is astonishing. This is not the time to dig deeper holes. The badger policy and cull needs to stop - it is now literally and officially, completely out of control.
Tom Langton is an international consulting ecologist to government, business and industry. He provides advocacy support to charities and pressure groups seeking justice where environmental damage is being caused to species and habitats. He has worked for over 40 years in nature conservation including common and protected species management, habitat management & restoration, wildlife disease investigation and invasive non-native species control.