Two pilot culls of badgers due to be proceeding in South-East England currently have been postponed until next summer. The culls were intended to prove that culling can prevent the spread of tuberculosis in cattle.
The immediate problem postponing the cull is that the UK government has newly estimated that the cull zones contain about twice as many badgers as initially thought. This means farmers will have to pay more in order to hire greater numbers of gunmen for the cull. However, the scientific justifications for the cull have also come into question. In early October, 32 senior British scientists signed an open letter to the UK government, expressing public doubt over the reasoning behind the cull.
Bovine tuberculosis (TB) is a very real problem in the UK. In 1998, farmers were forced to slaughter 6,000 cattle with bovine TB. By 2011 that number had risen to 34,000 cattle. The farmers themselves blame badgers for the spread of the disease, as badgers can infect pastures and even the air around them with the bacterium responsible for bovine TB, thus passing it on to cattle. They are thus keen to see the badgers culled, to reduce the number of badgers likely to spread the disease.
Initial surveys of the effects of culls suggested the tactic might have little or even negative effects. In 2007, interim conclusions from an experiment called the Randomised Badger Culling Trial (RBCT) showed that while infection rates decreased somewhat within the culling zone, badgers moving away from the cull actually increased infection rates directly outside the zone, leading to a net cancellation of any benefits found by culling.
Subsequent data from the RBCT sites has suggested that culling actually has some long-term positive effect on infection rates, and in December 2011, several UK scientists advised that culling might have a place alongside other methods of protection, such as the physical exclusion of badgers from farms, and regular herd checks. However, culling 1500 badgers over 150 square kilometres, over the course of four years, would only prevent 16% of new infections. Epidemiologist Christl Donnelly of Imperial College, London, who was responsible for the RBCT data, expresses some qualms over the usefulness of culling: “Is it worth culling so many animals for 16 per cent fewer infected herds? There, you get very different answers depending who you ask.”
John Krebs, at the University of Oxford, doubts the new pro-cull conclusions. He headed the team originally responsible for the RBCT, and he notes: “The pilot cull is flawed because it aims to remove 70 per cent of badgers without an accurate estimate of the starting number.”
The fact that the current culls have been postponed due to inaccurate population estimates reinforce this concern. Despite the enthusiasm of farmers and the support of the government, significant questions remain over culling. Hopefully some of them will be addressed before summer sees the guns loaded once more.
Illustration: Ruairidh Bowen