Use of farm buildings by wild badgers: implications for the transmission of bovine tuberculosis

Diseases transmitted from wildlife to livestock or people may be managed more effectively if it is known where transmission occurs. In Britain, farm buildings have been proposed as important sites of Mycobacterium bovis transmission betweenwild badgers (Meles meles) and cattle, contributing to the maintenance of bovine tuberculosis (TB). Farmers are therefore advised to exclude badgers from buildings. We used Global Positioning System (GPS) collars and remote cameras to characterise badgers' use of farm buildings at four TBaffected sites in southwestern Britain. Across 54 GPScollared badgers, 99.8% of locations fell >= 3 m from farm buildings. Remote cameras deployed in feed stores recorded just 12 nights with badger visits among 3134 store nights of monitoring. GPS-collared badgers used space near farm buildings less than expected based on availability, significantly preferring land >= 100 m from buildings. There was no positive association between badgers' use of farm buildings and the infection status of either badgers or cattle. Six GPS-collared badgers which regularly visited farm buildings all tested negative for M. bovis. Overall, test-positive badgers spent less time close to farm buildings than did test-negative animals. Badger visits to farm buildings were more frequent where badger population densities were high. Our findings suggest that, while buildings may offer important opportunities for M. bovis transmission between badgers and cattle, building use by badgers is not a prerequisite for such transmission. Identifying ways to minimise infectious contact between badgers and cattle away from buildings is therefore a management priority.