Will this cull work?

Scientists are still trying to establish whether killing badgers will have any real impact on tuberculosis in cows
September 18, 2013

"Meles meles has lived across Europe in its black and white form for two million years... public affection for this animal is unwavering." (© Nature Picture Library)

Villagers informing on neighbours for shooting badgers. Videos of screaming badgers shared on social media. Badger killers in hired 4x4s with high velocity rifles so scared that the police have installed CCTV at their homes. Pronouncements from Judi Dench and Dappy of hip-hop group N-Dubz. A luxuriantly-coiffured rock star fighting for “brock’s rights”. An environment minister who has staked his career on “bearing down on wildlife” but who also lovingly tended to Bessie and Baz, his pet badgers, as a boy.

A satirical novel that devised such details would be dismissed as preposterous. But the story of this autumn’s badger cull is not simply a comically improbable, very British farce. It shows how little we know of a resurgent disease, reveals a crisis in farming and exposes a cultural fissure between the urban majority and the tiny minority who work on the land. Its outcome is uncertain but as well as defining a few individuals’ careers it may redefine our relationship with the countryside and the people, and animals, who live within it.

From the moment Owen Paterson was appointed Environment Secretary and declared “And I eat meat,” it was clear he was far more stroppy than the average agricultural apparatchik. Brian May, the Queen guitarist and astrophysicist, has become Paterson’s bête noir, a human embodiment of badgerish values in television studios across the land. But above these compelling characters looms one figure held in higher esteem by the public than any other: the badger itself.

Even if your childhood heart was never moved by the brave Mr Badger in The Wind in the Willows, the badger is indisputably a fine and important native mammal. Meles meles has lived across Europe in its distinctive black-and-white form for two million years. In Britain, we have exterminated bigger predators—bears, wolves and big cats—but the badger, which might occasionally kill a hedgehog or rabbit but mostly directs its omnivorous appetite towards earthworms, has endured, testimony to its elusiveness and resilience.

For centuries we subjected the badger to obscene persecution. Working-class dog lovers (and the occasional parson and England cricketer) found that digging or “baiting” badgers was an appealing sport because of the badger’s surprisingly nimble tenacity when surrounded by bloodthirsty terriers. Finally, in 1973, the Badgers Act was passed, the first piece of legislation to give specific protection to a land mammal. Torturing badgers now landed people in jail. In a strange coincidence of history, just before the species was given full legal protection, a dead badger was found riddled with bovine tuberculosis near a farm in Gloucestershire where cattle had succumbed to the disease. Over the next 40 years, the badger would again be a target—not for grubby sadists with spades but for officials from the Ministry of Agriculture.

A variant of human TB, Mycobacterium bovis is a zoonotic disease, capable of passing to humans. It caused 5,000 human fatalities at its peak in the early 20th century before the pasteurisation of milk largely solved this public health hazard. In the 1930s, around a third of cattle had bovine TB in Britain. The compulsory testing and slaughter of infected animals dramatically reduced rates but, ever since the outbreaks in the 1970s were blamed on badgers, the government has got itself in a terrible tangle. A proposal to snare badgers was defeated by animal lovers in 1974. Officials then gassed badgers in their setts, which met with popular revulsion and was banned in the early 1980s after shadowy video experiments at Porton Down, the infamous biological and chemical weapons establishment, recorded badgers apparently in agony after being gassed. Culling continued with badgers “humanely” trapped and shot dead close to cattle TB outbreaks until 1996, but it was relatively uncontroversial because so little of it went on: bovine TB had virtually disappeared.

In 1986, just 235 cattle were slaughtered in Britain after testing positive for the disease. While the disease reappeared in cattle—4,949 cattle were slaughtered in 1988 rising to 38,010 last year—the badger population also rose, thanks to legal protection, milder winters and, ironically, modern farming’s habit of providing plentiful food through maize and earthworm-rich pasture. There is no scientific evidence to link bovine TB and badger population, but scientists agreed by the late 1990s that there was strong evidence that cattle and badgers transmitted the disease to each other, in both directions. Today, despite predictions that bovine TB will cost taxpayers £1bn over the next decade, there are almost as many knowledge gaps as scientific certainties. We still don’t know exactly how cattle and badgers transmit the disease to each other (it is believed to be mostly through indirect contact such as cows eating fodder contaminated with badger urine), making it difficult to design better biosecurity to keep badgers and cattle apart. We don’t know how many infected badgers are actually infectious, and capable of spreading the disease to cattle. We don’t know how much of cattle TB is caused by badgers: one scientific projection suggests as much as 50 per cent in certain hotspots. We don’t know how bovine TB might also be spread to cows by the bacterium’s presence in soil, water or other animals, such as deer. Extraordinarily, we don’t even know how many badgers there are in Britain. Sixteen years ago, academics estimated it to be 250,000 to 400,000, depending on the size of the average badger social group. That figure was a 77 per cent increase on 1988 and farmers claim it has exploded further in the last decade. Research commissioned by the Department for Environment, Food and Rural Affairs (Defra) will belatedly publish a new estimate next spring. All these uncertainties have been exploited by both sides in the vociferous debate over whether we should cull or save badgers.


As marksmen wait by setts in Gloucestershire and West Somerset for six weeks this autumn, required to dispatch 120 badgers each night to hit their target of 5,000 dead badgers, the most basic unanswered question is: will this cull work? The most quoted piece of science is the Randomised Badger Culling Trial (RBCT), an eight-year, £50m experiment to test whether culling badgers would reduce bovine TB in cattle. It calculated that four years of culling in a 150sq/km area would reduce bovine TB in cattle by 12 to 16 per cent over a nine-year period. In other words, culling badgers produces a modest reduction in cattle disease. John Bourne, the vet who led this experiment, concluded in 2007 that badger culling “could make no meaningful contribution” to the control of cattle TB. As John Krebs, the zoologist whose scientific review led to the trial, put it: “You cull intensively for at least four years, you will have a net benefit of reducing TB in cattle of 12 per cent to 16 per cent. So you leave 85 per cent of the problem still there, having gone to a huge amount of trouble to kill a huge number of badgers. It doesn’t seem to be an effective way of controlling the disease.”

The Labour government of the day agreed and badger culling was shelved; bovine TB would be tackled with tighter controls on cattle movement and, ultimately, the future development of vaccines for badgers and cattle. But the coalition government quoted the same science to reverse this decision. Some suspect this was a cynical political manoeuvre—David Cameron knew he would never obtain a parliamentary majority to repeal the ban on fox hunting and so a cull was a sop to disgruntled Tories in green wellies—but the data is sufficiently equivocal to permit this u-turn.

It is difficult to find a scientist who will publicly support the cull but this is not quite the point that Team Badger, the PR-savvy campaign convened by Brian May, would like it to be. When 30 eminent academics publicly criticised the badger cull for being “too small and too short term” they were careful to argue that “culling badgers as planned [my italics] is very unlikely to contribute to TB eradication.” Scientists object to the current cull but are not claiming that a different cull would have no positive impact. The panel of independent scientists commissioned by Defra to assess the humaneness, efficacy and safety of the cull won’t discuss their current task, but a year ago one member, Tim Roper, emeritus professor at Sussex University and the author of the definitive scientific book about badgers, talked to me at length and surprised me with his candour. He felt Bourne’s conclusion that culling badgers could make no meaningful contribution to reducing cattle TB was not valid, but he was not an apologist for the current cull either.

“If you are really committed to culling (as the government seems to be), then the most effective way to do it would be systematically. I’d also be much happier if they said, cull for five years and then vaccinate the relic [badger] population,” said Roper. Will culling work? “It depends what you mean by work. If enough badgers are killed, it will produce a temporary and slight decrease in the incidence of TB in cattle. If you think that’s ‘working,’ culling works. But that’s not what anyone would call a cure.”

One of the great ironies of the RBCT was that it provided the most compelling evidence yet that badgers spread bovine TB to cattle but cast doubt on the only way we could tackle it—by culling badgers. The RBCT researchers were stunned when the trial showed that culling badgers dramatically increased cattle TB at the edge of the cull zone. For Chris Cheeseman, a retired government scientist who devoted his career to examining badgers and bovine TB, here was proof of “perturbation,” a theory voiced by some badger experts for two decades. Culling disrupts badgers’ social structures, causing them to roam into new territories and spread disease more widely than normal. To reduce this, the RBCT trapped badgers in cages before shooting them and only culled animals for 12 days each year. Because the current cull is a “free” shoot over six weeks, Cheeseman and others fear it will make things worse.

There is another difference between this cull and the scientific cull: this time, farmers are doing the shooting. Farmers think scientists make hopeless killers; cage-trapping badgers is cumbersome and easily disrupted by animal rights’ activists. Farmers say they are better badger killers, and point to a much smaller, unscientific cull in the 1970s which wiped out every badger from Thornbury, Gloucestershire, and saw bovine TB disappear from cattle for a number of years. The RBCT, however, rightly remains the gold standard in the science of badger culling. Its weaknesses are the drawbacks in any British cull: elusive badgers will escape to spread disease and the public affection for this mammal is unwavering. Campaigners disrupt culls and even some farmers believe that culling is disastrous PR for their industry. If society is divided, a cull is bound to be less effective.

These peculiar features of a British badger cull are pertinent when Owen Paterson argues that other countries have only successfully reduced cattle TB by tackling the “wildlife reservoir” that most scientists believe helps sustain the disease. In Australia, water buffalo were slaughtered; in New Zealand, the brush-tailed possum has been tackled in an impressively thorough operation.

Leg-hold traps, cyanide pellets, anticoagulants, zinc phosphate, sodium nitrate and, most controversially, sodium fluoroacetate tipped from buckets borne by helicopters over enormous tracts of countryside: Paul Livingstone takes me through the ways in which possums are exterminated in New Zealand. Cattle TB peaked in 1994 with 1,694 infected cattle and deer herds in the country. In June this year, just 87 cattle and five deer herds were infected. Two months earlier, Paterson visited New Zealand to find out how they did it. “We spent a terrific day with him at the farm of the Chairman of our Animal Health Board,” says Livingstone, the experienced technical manager of TBfree New Zealand.

So Paterson should have grasped the differences between them and us. The possum is a non-native pest in New Zealand and culling it has overwhelming popular support and clear conservation benefits—native birds thrive where the possum is killed. The inadvertent poisoning of other mammals such as ferrets is good news, too, because every land mammal (bar a couple of bat species) is a non-native pest in New Zealand. This makes it much simpler both politically and ecologically to embark upon an unrelenting cull but Livingstone is convinced that there is still a lesson for Britain. “You need to deal with your wildlife host of infection with control,” he says. “How you do that is obviously up to you. It’s going to be expensive and it’s going to take a long time.”


There may be another lesson for Paterson from New Zealand, however. The British government probably made a catastrophic error when it assumed responsibility for killing badgers in the 1970s. For all the claims that this cull is “farmer-led,” it is still orchestrated by Defra. In contrast, the responsibility for tackling bovine TB in New Zealand is firmly devolved to farmers. “They are the ones bearing the pain, they are the ones who pay for the cull and they have a major say in how it happens,” says Livingstone. Farmers provide most of the funds for TBfree New Zealand and it was farmers who decided to cut the compensation awarded to bovine TB-hit peers to just 65 per cent of the market value of a cow (much tougher than the compensation doled out by the British government). New Zealand herds are classified as “infected” or “clear”: an “infected” farmer can sell animals from his herd but won’t get such a good price; a “clear” farmer can buy from an infected herd but loses his precious clear status. “We use market signals to make farmers make the right choice,” says Livingstone.

British scientists are cautious about taking lessons from other countries where the ecology and farming systems are completely different, but there is one other European country with a serious bovine TB problem: Ireland. In 2000, the Republic of Ireland slaughtered 40,000 cattle because of bovine TB. Last year, 18,500 cattle were killed. An Irish Agriculture Ministry official has attributed “much of the improvement” to its “badger removal programme.” Since 1985, 96,618 badgers have been culled by the Irish authorities, mostly using snares euphemistically called “stopped-body restraints”. Snaring badgers can cause horrific injuries and Ireland’s cull does not stop during the breeding season; if mothers are killed, cubs die of starvation in their setts. A badger cull this brutal may be more successful but its success also depends on the public not mobilising against it. And there is little dissent in Ireland, a country which may value its farming more and its wildlife less than Britain. Nevertheless, a few Irish critics maintain its cull is ineffective. “It’s to give farmers the impression that something is being done,” says Conn Flynn of the Irish Wildlife Trust. Last year Irish taxpayers spent €3.6m on culling 7,000 badgers; bovine TB in its six million cattle fell by just 55 animals.

For the Environment Secretary, there is no alternative. Owen Paterson’s job is on the line over the badger cull and he wants it broadened to 40 locations in England, already warning that it may continue for 25 years. If so, more than a million badgers could die. And yet every badger could be killed in Britain and bovine TB would remain: the main conduit of the disease to a cow is another cow, and this complex bacterium lurks in the grass, soil, water, and a myriad of other animals, from cats to camelids.

For critics of the cull, there is an alternative. Conservationists and celebrities argue that this cattle disease can only be beaten by a vaccine—for cattle. A cattle vaccine has already been developed and tested in Ethiopia and Mexico but it is not quite the attractive technofix it appears. An Ethiopian field trial found that the carcasses of 13 vaccinated calves had 56 to 68 per cent less disease than was seen in 14 control calves: in other words, the vaccine didn’t protect every animal and some animals simply caught a less severe form of disease. This is not to say the vaccine failed: a vaccine can rapidly reduce transmission by making individual animals less infectious. But any cattle vaccine would mitigate rather than remove the infection from our livestock.

“It’s not going to be a panacea,” says James Wood, professor of equine and farm animal science at Cambridge University. “There’s no magic bullet. We have a similar global problem with human TB and it’s massively re-emerging.” It is difficult for scientists to stimulate the immune system when tackling TB because it ebbs, flows and recurs. This also makes its detection difficult, as farmers know only too well. The current “skin test” used to detect bovine TB in cattle is woefully imprecise: some cows are riddled with TB but never test positive; others test positive and are slaughtered and subsequently found to have no TB: 22 per cent of new breakdowns (cattle herds found to have TB for the first time) in 2012 were only detected in meat at an abattoir—showing how much is missed by the “skin test.” Such failures suggest that most cases of cattle TB are caused not by badgers but by undiagnosed cows. Improving the skin test is tricky because bovine TB can “hide” in young animals or be masked by other diseases. We could increase the test’s sensitivity but that would lead to thousands more cattle being needlessly slaughtered.

A vaccine for cattle is also hindered by political obstacles. Apart from Ireland, only Spain and France have a small, emerging bovine TB problem and so the EU is opposed to a cattle vaccine because it would be difficult to distinguish between an infected and a vaccinated animal. British veterinarians have developed the delightfully named “diva” (differentiation of infected from vaccinated animals) test which works well in labs. Diva cannot be deployed until it has been trialled in the field, and it cannot be trialled without the EU also allowing the cattle vaccine to be tested. Anti-cullers find it strange that eurosceptic Tories are so unassertive about Brussels bureaucrats telling us what to do and argue we should go it alone, vaccinate our cows and then endure a ban on live exports because these are a tiny proportion of our trade.

Another alternative is to vaccinate badgers. Field trials of an injectable vaccine are encouraging. A four-year study by Steve Carter, senior scientist for the National Wildlife Management Centre, found the fast-acting vaccine reduced the risk of vaccinated badgers testing positive for bovine TB by between 54 and 76 per cent, depending on how the animals were tested. Carter also found that the risk of unvaccinated cubs testing positive when more than a third of the social group had been vaccinated was reduced by 79 per cent. In this way, even if a vaccine isn’t totally successful, it can build up what is called “herd immunity.” The Welsh government last year cancelled a planned cull and began a large-scale badger vaccination programme instead; in Gloucestershire, Somerset, Cheshire, Devon and Shropshire, volunteers have been vaccinating badgers on wildlife trust reserves for several years. But vaccination requires trapping and injecting badgers, which is time consuming and expensive: the Welsh programme cost £662 per badger in 2012. Farmers say it is crazily expensive to do this every year across Britain. Scientists, however, point out we only need to vaccinate in disease hotspots and every badger does not need to be treated to create “herd immunity.”

Rabies was finally defeated in Europe after an oral vaccine for foxes—placed in dead chicken heads—was first deployed in Switzerland in 1978; it was then successfully used in France, Germany, Belgium, Italy and Luxembourg and rabies declined in wild animals. An oral TB vaccine for badgers could be far cheaper than injecting large numbers of badgers. The coalition’s cancellation of five out of six vaccine field trials poses questions over the political will to develop one but Carter, who is part of the team developing the oral vaccine, denies that we are lagging behind other countries. It may be straightforward to find a bait attractive to badgers but researchers must also make the live vaccine cost effective and ensure it is taken up in big enough doses to be efficacious. The biggest challenge is to find a way of keeping the vaccine alive in a variety of environments and temperatures and encouraging enough of the badgers to eat it. Scientists need to also demonstrate that an oral vaccine doesn’t harm non-target species—especially cows, who could potentially swallow a dose and then show up as positive for bovine TB. “These are not insurmountable challenges but they are not insignificant either,” says Carter, predicting an oral vaccine won’t be licensed until 2019 at the earliest. And, he adds, throwing more money at this research won’t necessarily speed it up. Finally, more evidence is needed: it has yet to be proven that vaccinating badgers reduces bovine TB in cows, although if badgers are as toxic as farmers claim then it should be the case.

Vaccines offer an appealing technological fix but there are more radical alternatives. Some say bovine TB poses little risk to human health and we should learn to live with it, although having cattle riddled with the disease would destroy the credibility of our farming industry. Others argue that TB is a disease of poverty and a result of ever more intensive farming. Artificial insemination within the dairy industry has bred prolific milk-producing cows that old countrymen say are Ferraris rather than Land Rovers: modern, high-performance machines, far more likely to break down. If we had selectively bred cows for immunity from TB 40 years ago, we probably wouldn’t be in this pickle today. Another scientific challenge is to search for TB-resistant genes. “If resistance genes can be identified within the highly structured dairy industry you could fairly quickly see an increase in resistant genotypes across the dairy population,” says Wood. More research is required and the cull is a missed opportunity because the dead badgers will not be systematically tested for bovine TB, which could give us an idea of infection rates and infectiousness.

But science has its limits. Interrogating our own feelings for Meles meles, we could ask a similar question of both sides. Why do farmers so desperately want to kill badgers when the best scientific study estimates it might reduce cattle TB by 16 per cent in the local area? And why do campaigners care so much if a few farmers want to shoot a relatively small number of a common animal to control a disease? Farmers argue that a 16 per cent reduction is more than their profit margins, so their livelihoods are at stake; badger lovers point to all the other, less destructive steps we could take to reduce this disease.

It is not just farmers but scientists including Tim Roper and James Wood who question the rationality of popular opposition to the cull. A black and white generalist, a great success story, the badger is not so different from the magpie, which is routinely killed. People who would poison a rat without a second thought are devastated by a cull of 5,000 badgers when 50,000 are massacred each year by the motor car. “I do understand the cultural origins of badger protection but it’s illogical that the badger is protected and the fox is not,” argues Wood. Or, as one farmer said to me: “Take the blimmin’ protection off. It wouldn’t cost the government any money and farmers wouldn’t go out and shoot badgers all night because we’re too bloody tired in the evening.”

Of course there are rational ethical and moral objections to a cull. For animal rights activists, every life is sacred and we have no more right to swat a fly than shoot a badger. For many conservationists, a cull is not black and white: as self-appointed masters of the universe we are obliged to maintain a balance of nature as best we can. Sometimes we must reduce one species to save another. Each year, conservationists protect rare plants and insects by culling deer and no one protests. But this badger cull is not about a balance of nature. It is controlling a wild animal that threatens our immediate economic interests. And it leaves one awkward question hanging in the air: do we want to farm in a way that is dependent on killing significant numbers of a native mammal? And if not, will we pay for an alternative?