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BADGER culling could be responsible for spreading bovine TB (bTB) more widely due to surviving badger populations travelling further afield during and following a culling episode. According to new research carried out by the Zoological Society of London’s Institute of Zoology and Imperial’s MRC Centre for Global Infectious Disease Analysis, badgers cover more ground after a cull than they would do ordinarily – some 61 per cent more land each month. During a cull, they also visit 45 per cent more fields each month, and the odds of a badger visiting neighbouring territories each night increases 20-fold. The results appear to show that as individuals are removed from neighbouring groups and territories open up during a cull, surviving badgers tend to explore new areas. The changes in their travel habits are evident from the onset of culling, meaning badgers could spread the infection to others or cattle as they travel before being culled. The researchers believe that this change in movement could increase the risk of bTB transmission both in cattle and other badgers, exacerbating the problem the cull is trying to solve. The research team examined badger movements in 67 badgers across 20 cattle farms in four distinct areas, collecting GPS-collar data between 2013 and 2017. One area had a badger culling license, while the other three did not. They found that, while badgers covered more ground during a cull, badgers spent less time outside of their setts – 91 minutes less per night out. This, they believe, could be linked to reduced competition and increased food availability, as other badgers are removed. Lead author Rosie Woodroffe said: ‘As badger-to-cattle transmission is likely to occur through contamination of their shared environment, and TB bacteria can remain viable for long periods of time in the environment, the effects of increases in ranging behaviour could create a source of infection for several months – long after the individual badger has been culled’ In contrast, she said studies have shown that vaccination prompts no changes in badgers’ ranging behaviour. Badger culling is now authorised in 40 areas of England, with four-year licenses that are granted by Natural England. Last year, a review on the UK’s bTB eradication strategy was published, chaired by Sir Charles Godfray. The report concluded that it was important to not ‘over-emphasise’ the role of wildlife in the transmission of bTB, but said that the evidence showed badgers did pose a threat to local cattle herds. The report went on to say that the only viable option to culling was vaccination, and advised that a trial be carried out to test its efficacy, with all areas adopting it should the trial have positive results. In the research study, published in the Journal of Applied Ecology this week, the researchers agreed that vaccination was a viable option to replace culling. A spokesperson for Defra said that the government policy already takes into account ‘a potential increase in badger movement by ensuring there is an intensive cull across an area’. They continued: ‘There is no single measure that will provide an easy answer to beating the disease and we are pursuing a range of interventions to eradicate it by 2038, including tighter cattle movement controls, regular testing and vaccinations.’ Speaking at a ZSL event this week, Woodroffe said while no experimental Is the badger cull actually spreading bTB?