Recently, the government announced that they would be extending badger culls (which have not worked) not only to other ‘high risk’ areas for bovine TB but also granting licenses in new ‘low risk’ zones across the UK as well.
I was going to write a long, angry and thoroughly-hyperlinked post-rant railing against the cowardice and incomprehensible idiocy of this policy. Then I went a little further in my research, and come to the conclusion that tt is a very complicated matter, though my feeling is that the cull is still wrong, both from a moral standpoint and as a practcial measure.
Bovine TB (bTB) has been a serious problem for farmers in the UK for a century or more, causing hundreds of thousands of animals to be slaughtered and costing hundreds of thousands of pounds. It has been estimated that the disease has cost the taxpayer 500 million over the past 10 years. TB is a zoonotic disease- it can spread between humans and livestock species as well as wild animals such as badgers and otters. Badgers being implicated in the spread of bTB between herds in the early 20th century, intensive badger culling was part of the strategy to quell the scourge of this disease, along with monitoring and movement restrictions.
With it’s resurgence in the 1980’s, ‘Randomised Badger Culling trials‘ were put in place in 1998-2007. Marksmen were employed to kill animals intensively over 100 square km. about 11000 out of 300000 of the badgers in Great Britain were culled. ‘Reactive’ Culling (localised response to TB infection) increased TB incidence by about 20% in the fringe zones around culling areas, and had only marginal effect on incidence rates going forward, and those only after several years of culls. ‘Proactive’ culling (maximising kills over a wider area) significantly reduced badger numbers and TB rates lowered by about 23%, but also caused infected badgers to disperse and increase transmission in fringe zones. The resport on these trials concluded that strategically overcoming the negative impacts of culls was ‘not achievable on any useful or practicable scale’.
Against almost all scientific advice, more trial culls were carried out in 2013 in Somerset and Gloucestershire. This move was vehemently opposed by over 30 eminent scientists, and even the government scientific advisor, Lord Krebs, who designed these trials, described them as ‘a crazy scheme‘. This time, farmers and landowners were licensed to shoot the animals themselves, ironically under the Protection of Badgers Act (1992). Again, any noticable reduction in bTB rates was only seen after two years of culling (21% and 58% in Somerset and Gloucestershire, respectively). In addition, in most of the trials that have been carried out, buffer zone showed increased bTB rates: culling tends to disrupt settled badger setts, causing animals to foray into new areas and increase the spread of disease around cull zones.
The 90’s trials suggest that culling is only effective if at least 70% of badgers are killed. The Somerset-Gloucestershire trials aimed to to reduce badger populations by 70% in six weeks. A very lenient measure of kills showed that 58% of Somerset badgers and 30% in Gloucestershire were killed, but a more rigorous analsis by the independent panel suggested <50% in both zones. This monitoring was rather hampered by the fact that the badger population was not known before the trial started.
Professor Rosie Woodroffe, a scientist at the Zoological Society of London, took a firmer stance when speaking for an independent investigative panel into the Somerset-Gloucestershire trials, arguing that they showed ‘unequivocally that the culls were not effective and that they failed to meet the humaneness criteria’. Woodroffe suggested that there was no real monitoring of the kill-rate – when the kills exceeded the quota, it was simply extended, when they failed to meet it, it was simply reduced.
The success of such trials are very difficult to monitor, both because of the complexity of monitoring wild animal populations, and because of the nebulous cause-effect relationship between badger numbers and TB. A study published in 2017 by Brunton et al. assessing the Somerset-Gloucestershire culls argued that the data were insufficient to confidently conclude that culling reduces bTB rates. The results were damn difficult to evaluate due to this being not a scientific experiment, but more of a ‘suck it and see’ massacre.
Apart from monitoring vagaries, and the fact they just, well, didn’t really work, there was another serious issue with the culls. About 18% of culled badgers in the Somerset-Gloucestershire trialstook longer than five minutes to die, failing any reasonable standard for humaneness. Given the last to protect badgers from cruel practices such as badger baiting, or the furore about the seemingly brutal death of foxes from hounds (which takes less than 10 seconds), it is rather ironic that the government would pay for most of the badgers in some areas to suffer slow, bullet-wound deaths.
So what does the government say in the face of continued bTB strife? On the 24th May they went with more culls, in both high and low TB incidence areas, using a license and bounty system – 50 quid a badger head. This bounty seems generous, but will probably save money on the professional cull carried out inthe 90’s. There have been protests against the cull, but nothing like on the scale of the politically and socially charged dispute over fox hunting a couple of decades ago. The policy seems despicable, a clear example of the broken relationship between policy and scientific evidence, but there may be mediating factors.
Vaccinations, herd testing, movement restrictions and biosecurity are the primary alternative bTB control methods, and a tightening of these controls was advised and implemented after the 90’s trials. TB is a very complex and insidious disease- it can’t be tackled with a single method.
Vaccination of cows and/or badgers, is heartily favoured by organisations such as the Zoological Society of London and the RSPCA, and basically every prominent zoologist in the UK. Farmers also seem to favour vaccination as the primary strategy. But the government argues that “vaccination is unlikely to lead to disease eradication in the badger population within an acceptable time limit”.
Arguably, a 2012 vaccination trial of badgers did prove the difficulties of delivering the vaccine, especially in efficacious quantities and to enough animals. Injectable vaccine cost an estimated £2000-4000 per square km. That’s about 660 quid per badger. It is not cost-effective. An oral vaccine may be possible, but is yet to be developed in a form that could survive a badger’s stomach. The support from farmers and other stakeholders required to get such a scheme off the ground for development and implementation seems unlikely.
Cattle vaccination is going to be implemented as part of the government strategy, and was first shown to be effective in cattle in 2011. The front line vaccine against bTB, BCG is currently not yet well understood in an agricultural setting. It creates a complicating factor in that vaccinated cows are more likely to test positive for bTB in the IFN diagnostic test, confounding another key bTB control measure- regular bTB testing. It’s efficacy and longevity are difficult to determine in a farm setting too, but repeat vaccinations would probably have to be given.
An ecological point is also the fact that, perhaps, the badger populations are higher than they have been in the past. Just as foxes have benefitted from ‘mesopredator release syndrome’, the removal of top predators freeing up a whole realm of ecological niche space, badgers may have overgrown their historical numbers as a result of there being plenty of food, no predators, and legal protection to boot. This can have detrimental effects on other species- Matt Ridley makes a strong case for the plight of the hedgehog as a result of badger excess, for example.
Despite these arguments, what is the end game here? Are we going to keep badger populations permanently lower? We are very good at eradicating large mammals, as the sad tale of the thylacine, bounty-hunted to nought in the 1920’s and 30’s because of it’s assumed sheep-rustling. Keeping pest mesopredators out has not worked in other places: the 120 year-old, 3500 km ‘dingo fence’ in Australia is a bizarre piece of ecological engineering, coupled with culling, which has done nothing but create more problems for sheep farmers and wildlife.
Maybe, rearing large numbers of animals in intensive conditions, whilst breaking the usual ecological syetems in the habitat in which they live, just doesn’t work. Intensive monocultures have repeatedly succumbed to disease. Increasing the ecological intervention seems like a hiding to nothing, purely a political gift to desperate farmers fighting an insidious threat.