European badgers can catch and spread the form of tuberculosis that strikes mainly cattle, but farmers and animal enthusiasts have debated whether killing badgers would protect herds. Two studies now reconcile earlier contradictory findings.
New results from a study in Britain suggest that the boundaries of a study area make a difference, says Christl A. Donnelly of Imperial College London. She and her colleagues looked inside 10 100-kilometer-square culling zones where badgers had been removed, regardless of whether or not cattle were infected. There they found a 19 percent reduction in bovine-TB incidence in the cattle. Yet when the researchers looked at land surrounding the culling zones, they saw a 29 percent TB increase. The government-funded study's results w