JOIN USThe future of the badger in England is threatened by the powerful farming community, which is fighting for its large-scale culling. Also, culling alters the ecology of badgers and disrupts their social structure, writes Deepthi Chimalakonda.
The European badger, Meles meles, a social yet territorial animal, is common throughout Europe, Russia and some parts of Asia. It is an opportunistic forager characterised by its varied omnivorous diet. An estimated 3,00,000 make England their home. Heavily hunted decades ago, it is now protected under the Protection of Badgers Act 1992. Killing or interfering with badger ‘setts’ is an offence.
Yet, the future of the badger in England is threatened by the powerful farming community fighting for large-scale culling of badgers.European badgers have been implicated in transmitting Mycobacterium bovis to cattle, responsible for causing bovine tuberculosis (bTB). bTB, a communicable disease spread by inhaling bacteria-infected air, places a heavy burden on the British cattle industry often leading to large-scale slaughtering of cattle.
The UK government recently announced its plan to implement pilot culling of badgers this summer in Gloucestershire and Somerset so as to curb the spread of bTB. The decision caused uproar amongst wildlife NGOs and environmental groups who argue, based on scientific evidence, that badger culling will not end bovine bTB. Yet, the government’s decision strongly backed by the National Farmers’ Union reminds us of the perils of ill-informed science, our shortsightedness and politics behind the ruling.
Badger-to-cattle transmission
The extensive multi-million pound randomised badger-culling trial (RBCT) or the Krebs trial showed some evidence of badger-to-cattle transmission. If badgers are culled, the disease could be reduced by about 15 per cent under certain conditions, says the study. In the last ten years, bTB had cost the English taxpayer an estimated £500m. Looming economic losses, and needless to mention, panic, had forced the farmers to be the frontrunners for the culling-campaign.
There is compelling scientific evidence showing cattle-to-cattle transmission to be equally, if not more, responsible for bTB spread. The Independent Scientific Group that submitted its report to Department for Environment, Food and Rural Affairs (DEFRA) even states that cattle-to-cattle transmission could be the cause for spread of disease to new areas.
Culling also alters the ecology of badgers and disrupts their social structure. Culling leads to reduction in number of individuals increase in their home ranges and frequent movements into and out of the groups.
The social ‘perturbation’ increases contact rates between individuals. Studies showed that bTB prevalence in badger social groups increases, especially those neighbouring removals. Culling-induced social stress augment disease spread.
Tuberculosis in cattle dates back to the early 1900s. Dairy products from diseased animals arrived at markets. Their consumption affected human populations. In the 1930s, about 40 per cent of cattle were infected and about 50,000 people had TB.
Milk pasteurisation and area-wise eradication programmes greatly reduced the disease in humans and cattle. By 1960, all cattle in the country were tested at least once and reactors eliminated. By the end of that decade, England was almost TB-free. The first reported case of badger bTB was not until 1971 when a badger from road kill was tested positive for bTB post-mortem.
Subsequent analyses of badgers from road traffic accidents (RTA) revealed epidemiological link between the two species. As a result, badgers were culled by gassing for more than five years. Live trapping and subsequent shooting replaced this brutal act in the 1980s.
The same decade witnessed intensification of cattle husbandry techniques, increased herd sizes, over wintering cattle in sheds and growth of maize as a vital crop. The first three enhanced cohesion among cattle increasing the risk of disease spread. The maize movement may have attracted badgers who also benefitted from the implementation of The Protection of Badgers Act 1992.
Meanwhile, cases of bovine-badger-TB grew immensely in the next two decades and showed high spatial correlation leading to labeling of badgers as the ‘cause’ for bovine bTB. Hitherto scientific evidence failed to establish badger-to-cattle transmission to be higher than cattle-to-cattle transmission. Yet, the present tense involving pro-culling judgement seems absurd to any rational human being. The future, tense and uncertain for the badger!
Alternatives
Non-lethal solutions exist. Research on vaccinating badgers showed about 74 per cent reduction in disease prevalence in badgers over a four-year time scale. The natural bTB prevalence rate in badgers is about 10-20 per cent that upon rigorous vaccination would greatly lower disease incidence. In captive badgers, the BCG vaccine significantly suppressed the advancement of mycobacterium bovis bacteria.
The most obvious and practical solution would be cattle vaccination. The British government spent an estimated £23m into research and development of cattle vaccine so far and pledged a few more millions for further research. It is clearly recognised that cattle could be the largest vectors of the disease and the vaccine identified as being effective in preventing breakdowns and disease transmission. Research on the efficacy of cattle vaccine elsewhere showed it to be about 65 per cent effective. Cattle vaccination is not the cure-all solution. But so is badger culling. Then why is the government rooting for the latter?
The European Union Legislation currently prohibits cattle vaccination. Vaccinated cattle test positive for the standard TB tests namely the tuberculin skin test, leading to false-positives in BCG-vaccinated but TB-infected cattle. Tests to differentiate whether vaccine or TB causes the positive skin test are currently under development. The main concern, however, is that vaccination will lead to a ban on export in live cattle and dairy products by other European countries.
While the live-animal trade is relatively small, it is the £1.1m meat and dairy product business that the government is not ready to lose.The evidence for cattle-to-cattle transmission is as strong, may be more, than badger-to-cattle-transmission. There is a library of scientific literature stating the fallacy of causal relation between badger and bovine bTB and that culling will not eradicate bovine bTB.