In some areas of the UK, deer (especially fallow deer due to their gregarious behaviour) have been implicated as a possible reservoir for transmission of bovine tuberculosis, a disease which in the UK in 2005 cost £90 million in attempts to eradicate. In New Zealand, deer are thought to be important as vectors picking up "M. bovis" in areas where brushtail possums "Trichosurus vulpecula" are infected, and transferring it to previously uninfected possums when their carcasses are scavenged elsewhere. The white-tailed deer "Odocoileus virginianus" has been confirmed as the sole maintenance host in the Michigan outbreak of bovine tuberculosis which remains a significant barrier to the US nationwide eradication of the disease in livestock.