For more information and background to the Wildlife Trust’s view on badger and TB see http://www.wildlifetrusts.org/badger-cull.
To try and scientifically test whether culling badgers would reduce the disease, ‘Randomised Badger Culling Trials’ were carried out from 1998-2007. These were led by Professor (now Baron) John Krebs and cost £50 million.
The trial established that cattle to cattle transmission of the disease is the most prevalent route of infection and that stopping this should be a priority (through good farm biosecurity for example). The trials also revealed that, although there can be some short-term reduction in some high bTB areas after a cull, this is only a short-term effect (less than four years) and only if the cull eliminates a very high proportion of the population. This is because in most cases culling disrupts stable badger territories leading to more badger movements and spreading of the disease (the perturbation effect). The trial concluded that a reactive cull of badgers resulted in significant increases in bovine TB and a proactive cull, while controlling TB in the cull area, contributed to an increase in TB in surrounding areas, and would not be cost effective.
The Independent Scientific Group on Cattle TB concluded in its final report (2007) that it was: “unable to conceive of a system of culling, other than the systematic elimination, or virtual elimination, of badgers over very extensive areas, that would avoid the serious adverse consequences of perturbation”. Baron Krebs and Professor John Bourne – a vet who chaired the Independent Science Group on bTB have publically stated that culling is not the answer to cattle TB control in Britain. However Sir David King (then Chief Scientific Advisor to the Government) interpreted the data differently and recommended that culls could be effective, but only if very well planned and executed and covering at least 265km². Therefore the current Government is pursuing badger culling.
In 2017 the cull took place in 19 areas in Gloucestershire, Somerset, Dorset, Cornwall, Devon, Herefordshire, Cheshire and Wiltshire. The licences allow badgers to be killed every year between 1 June and 31 January.
In 2018 the Government consulted on proposals to increase the number of cull zones and also to extend the cull to Low Risk Areas – including Sheffield and Rotherham – despite low cases of bovine TB in these areas. In May 2018, the Government confirmed these changes would be introduced. In November 2018 the Government published an independent report (The Bovine TB strategy review) led by Professor Sir Charles Godfray, the findings of which show a significant change of emphasis is required in regard to the effectiveness of badger culling, improvement of farm biosecurity measures and rates of badger vaccination. Read our response to the report here.
In October 2019, a study led by researchers at ZSL (Zoological Society of London) and Imperial College London (Effect of culling on individual badger Meles meles behaviour: Potential implications for bovine tuberculosis transmission) found that culling drives badgers to roam 61% further afield – helping to show how culling, despite intended to reduce bovine TB transmission, can potentially increase the risk of spreading the disease to cattle and other badgers.
In December 2019, a study by scientists from 12 institutions across Britain and Ireland showed for the first time by using direct evidence that transmission of TB by cow-to-cow is more significant than badger-to-cow. Scientists undertook whole genome sequencing of different strains of bovine TB to detect how it moved between cows and badgers in Woodchester Park, Gloucestershire. They found that transmission within each species was more frequent than from one species to another. Click here to read their analyses, which was published in the journal eLife on 17 December 2019.
Information about the specifics of the licensing of badger culls can be found on the Natural England website.
Find out more about what the Wildlife Trusts are doing to promote vaccination and to protect badgers around the country by visiting the badger pages on The Wildlife Trust’s website. Included is a great video as well as a useful ‘infographic’.
The Oxford Martin Programme on the Future of Food has produced an excellent summary of the ‘Natural Science Evidence Base Relevant to the Control of Bovine Tuberculosis in Great Britain’.