European bison were extinct in the wild by 1927 but have been successfully restored through captive breeding and reintroduction.
Captive breeding programme bison face welfare challenges from confinement in spaces inadequate for their large size and ranging behaviour. Translocation to new release sites causes stress. Newly released animals must establish territories and social hierarchies in unfamiliar environments. Interactions with domestic cattle risk disease transmission including bovine tuberculosis. In the UK release site, monitoring of the small founding population is critical to detecting welfare issues early.